KensingtonExpert Trackball Mouse (K64325), Black Silver, 5"W x 5-3/4"D x 2-1/2"H

I have written a complete review of this device in its Wireless Version which is no longer manufactured. Its overall design has been well described in these numerous reviews. I would like to address a few of the complaints registered in some of the reviews on this thread, at least IMHO:1) The bearings on which the ball rests are different, and overall, there is no significant change in build quality which is more than adequate.2) Initially I also had some difficulty on Win7/64 with Trackball Works 1.04 and 1.01, the European version which tech support recommends when you call in to complain about the former. In my case, this represented some sort of software conflict which was no longer the case when I gave it another try after having had to reformat and reinstall my system for other reasons. Initially, although I could program the trackball without difficulty, it would intermittently hang, or my computer would crash. Since the reinstall, now for about 3 months use, Version 1.04 works absolutely fine with this Expert Mouse, but install the software before connecting the device, as mentioned. Absolutely NONE of the initial problems have recurred. Trackball Works has some problems with complete programming of the Slimblade Trackball version and Kensington is working on it, with a supposed upgrade to the software due in March, at least at the time of this writing.3) The ergonomic issues raised by some of the reviewers are legitimate, but it depends a great deal on the individual user. I agree that the "wrist rest" supplied is not a very successful solution. Some will prefer the flatter format of the Slimblade, but I don't think the four buttons work as smoothly as those on the Expert, and are very dependent on where you place your fingers on them, which is not the case with the latter which are nicely designed. At work, I use this trackball for hours on end, now for years, in our radiology department, scrolling through images, and have had absolutely no wrist or finger pain. One of the tricks is to operate the mouse with your hand canted to the right at about a 30 degree angle which helps to obviate more extreme wrist extension. Give your hand and wrist a brief rest by changing position every few minutes which can easily be done automatically during the workflow since you aren't gripping something. Any pointing device without rest will be a nuisance. For those who are particularly sensitive, place a small bean bag place under the palm of the hand, not the wrist. Since you aren't spatially moving the unit, it is not intrusive, if you buy a proper sized bag.4) Complaints about the scroll ring, IMHO, are entirely unjustified. It works very well. I have had no problems with its function on this unit, my previous wireless mouse, or any in our Department at work.5) Complaints about the ball's being sticky and insensitive are also groundless, IMHO. You will find slight "newness", reflected in slight stiffness,when you first use the unit. This will clear promptly, and even more quickly if you just spin the ball for a couple of minutes with moderate downward pressure to break in the interface between the support pins and the ball. Periodically clean the ball with a little soap and water, then alcohol to restore a smooth surface, and repeat the conditioning routine, in an abbreviated form. At the same time, inspect the pins on which the ball rests for accummulated dust and debris, and make sure they're absolutely clean. Works like a charm.For those that don't like the scroll wheel, try the Slimblade where scrolling is done via the ball itself, turned transversely. That works well....it's just a matter of personal preference. I personally prefer the larger ball on the Expert versus the Slimblade, and the independent scroll wheel. The interface cable on the Slimblade is a little more robust and less prone to kinking if you move the trackball around quite a bit, for example, if you're also using a graphics tablet on which you seat the trackball. In any case, I don't think it's an issue, particularly if you take a bit a care of how you set the mouse down so that it isn't repetitively stressed with a kink. BTW, I couldn't find the magnet that one reviewer talked about at the bottom of the receiver for the ball. All that's there is the optical pickup. BTW, if you use the Intuous 4 Wacom tablet, the RF mouse they supply is greatly improved over previously, and is nicely programmable, except for no control over acceleration which some users may find a distinct negative.Bottom line: HIGHLY recommended after years of experience using this trackball. Works perfectly well with Win 7/64.

I bought this to replace an older one of the same model, that has always (from new) had a crappy scroll ring. I tried everything, lube, taking it apart and cleaning, etc. It just never was smooth and accurate. Something I have read in other reviews of the same product. Not smooth scrolling, rough feeling, inaccurate scroll. etc.I figured I'd take a chance, since some of the reviews seemed not to mention any of this. I got it, set it up and it's EXCELLENT! No more rough scroll, inaccurate scroll, or any issues at all....so far. I haver read of connection problems, even wired, but so far, no problems on a 2021 iMac, with Apple M1 silicon.I have read complaints on the Kensington Works software, especially from some Mac users. I got away from that entirely a while back, using the (paid version) of "Steermouse" . It takes a bit of a learning curve, but you can set nearly anything you want, and it just WORKS.I hope this review helps any other long time Expert Trackball users, although I may have just gotten lucky??! This device does have a rocky track record of reliability and correct operation, so your mileage may vary. But I will say, once set up and working properly, it is a very nice pointing device, if you are into trackballs. I also have a CST L-trak, but keep coming back to the Kensington. It's that scroll wheel...when it works right!

I know a lot of people don't like trackballs, but for those who do, it is extremely well built and durable, this is replacing the same model I bought 10 years ago. It's perfectly ambidextrous, the ball lets you infinite scroll, it's wireless, bluetooth and it works on *any* solid surface, including on my knee while traveling, programmable buttons. For the price you can't beat it!

As a long time user and huge fan of the older model (that was a different chassis shape) I'm giving this USB Expert Mouse 4 stars out of 5 initially and I will go back and re-review this product further once I get to spend more time using and evaluating it and I really get to compare it to the older version. My only reason for replacing my old one after so many years is because I need USB for a KVM switch and my old one is Serial/PS-2 only.I've read a significant number of less than favorable reviews on here about this newer version that were saying how some users feel this model has either one of 2 problems or both. These negative reviews were mostly from either first time trackball users who were only used to moving a mouse around their desk surface with their arm and had no idea what to expect with a track ball or from users of other (cheaper) brands who were looking for better quality but chose to complain about what they claimed to be a heavy, stiff, bulky movement of this unit's big trackball but some of the lower star reviews it received were also from users who went from older models of the Expert Mouse to this new redesigned model.The other complaint had to do with wrist position comfort and again came from both new users and a few who had an older Expert Mouse version like the one I've been using daily for over 20 years, many of which didn't know what to expect when switching from a mouse to a track ball, and quite a few who already had wrist problems before they bought one of these units to try.Note that my old Expert Mouse trackball still works, even after 20 years of daily use, but I needed USB for a KVM and I couldn't come up with a working PS/2 or Serial to USB converter solution that would stay working after being passed through the USB KVM and/or didn't cost more than the KVM and this track ball cost when purchased together so I opted to replace my vintage Expert Mouse with this one and time will tell if I'll be as happy with this new one as I've been with the original but here are my initial findings at the beginning of day 1 with this new model...As I just took it out of the box, unplugged the PS/2 plug of my 20 year old Expert Mouse, and plugged this brand new restyled USB Expert Mouse into my PC here is what I've determined so far...For whomever has complained about the stiff, hard ball movement, as a regular daily user of an original Kensington Expert Mouse that I've had since I bought it new literally 20 years ago (in the days of Windows 3.1) I must say that they are wrong, period.Although it doesn't feel like it's hovering weightless beneath your fingers as the Logitech products with their smaller ball tend to feel (especially after they literally get greasy from oily hands), it also doesn't feel all slippery with no user feedback like the Logitech products do, and the "massive" ball (as they called it) not only glides as smooth and easy on this new model as the original Expert Mouse did, the ball also has that same solid feel with great control and excellent feedback beneath your fingers as the older models did too!At my office there are several audio editing workstations with Logitech track balls on them (which suffer from left button failures and need to be replaced at least annually) so I'm totally familiar with both brands and types of these products and I'm okay with using the tiny ball and the crazy slickness of the Logitech track balls compared to a traditional mouse but I've always preferred the feel and motion of the much larger ball in my vintage Expert mouse in comparison to those Logitech products and so far the ball in this new version Expert Mouse feels exactly the same to me as my old one has for so many years.I had read in a number of reviews (and some complaints) that the ball's movement was stiff and just had to be broken in over a few hours or a few days of use while others said to literally oil it (which seems excessive) so as soon as I took it out of the box I lifted the ball out of its' opening, rubbed my finger tips across each of the 3 balance points that the ball rests on several times then rolled the ball around between my two hands for a moment, then dropped it back into its' opening and tested the movement and I was totally happy when I found that right out of the box this brand new USB optical model feels EXACTLY like my 20 year old roller driven Serial/PS2 model Expert Mouse does... Smooth, fluid, and well made.Now for the negative reviews with wrist position complaints I can see how some people could be somewhat unhappy with it but it doesn't feel bad to me so far, just a bit different.As a couple of other vintage Expert Mouse users have also stated, this new curved front design does feel very different beneath my hand than the old model from the moment I set my hand down on the ball. The old model was straight across with a high lip which occasionally would begin to slightly bother a small area of my hand between my wrist and first thumb knuckle during long audio editing sessions with lots of left-click/drag thumb action but it gave good lower palm support and was never uncomfortable or a big deal at all.Kensington has obviously put some thought into this and eliminated that big straight high edge front lip which lets me set my wrist and the edge of my palm directly on the desk and that actually feels nice but that also places the ball under the middle of my hand (closer towards my palm) instead of under the middle of my fingers (closer towards my finger tips) which gives the ball a different feel, initially a bit awkward and less familiar but time will tell how my brain chooses to adapt to the new design...If I move my palm back away from the curved front lip a little bit then it places my fingers on the ball where I'm used to with the older model but without the big front lip of the older model the mid-palm support that was provided by the old lip isn't there which leaves the overall weight of my hand kind of pulling down on my fingers a little as they're resting on the ball in the position I'm used to feeling beneath my fingers on my older model of Expert Mouse. I can see where someone with pre-existing wrist issues might not feel totally comfortable with this model beneath their fingers, especially if they have long fingers, but I'm optimistic about the new ergonomics and comfort of my entire wrist being able to rest on the desk and we'll see how my hand chooses to acclimate to the redesigned ergonomics of this newer model once I spend a bit more time using it.I have fairly short fingers, for example I can play a piano reasonably well and I can somewhat manage to play a guitar too but my speed on the guitar is slow and somewhat sloppy because it's a struggle for my fingers to fully reach across the neck and spread as needed around the frets and strings for some chords.Someone with longer fingers may or may not feel like they need more support than this newer model offers compared to the older versions and the new removable palm rest may or may not be a good solution for those who want more wrist support, I don't know yet.At first, without the palm rest I like how my palm rests comfortably on the desk but with my palm up against the contoured front of this model the ball position feels different from the old one under my fingers.With the palm rest on it my fingers can go back to that familiar position on the ball but based on my seating height and arm reach to me the palm rest gives good support but feels a bit thick, raising my wrist considerably higher than I think I'd prefer so far...But since I haven't had much time to use this newer Expert Mouse yet I'll try it with and without the palm rest for a while and post my findings once I decide what feels best for me, or if for some unexpected reason I happen to decide that I don't actually like it with or without the palm wrest compared to the older model's front lip. Time will tell.Therefore, right out of the box I'm giving it 4 stars as I'm assuming it's as well built as my 20 year old one is plus I've already seen that the negative reviews about the ball movement are entirely wrong but the concerns about the redesigned ergonomics are going to take some time and use for me to make an informed decision about, and the scroll ring sounded like a welcomed addition as that's the main reason the bottom left button on my vintage unit occasionally gets a little intermittent during a long day's use after 20 years in service but I'm not sure whether the new model's scroll ring's movement will loosen up or not and I'm not sure if it will stay working when using a KVM switch as most scroll wheels stop responding after switching back and forth between PC's on a KVM which is not the fault of the mouse/track ball but may render that feature useless for me anyway, time will tell on that one too.First impression, I can see why some people might complain about the redesigned ergonomics but the movement of the ball is just as smooth and familiar as the old ones were and so far on day 1 with this new model it's obvious that the ergonomics have been redesigned which does alter the way it feels along the bottom edge of your palm compared to the older models but so far with my first few minutes of use I'm already satisfied with my decision to purchase this new model (only to get the USB functionality that I now need) and I'm confident that I'm probably going to be just as happy with this product as I've been for 20+ years with its' predecessor...UPDATE: Basically 60 days into ownership and the revised ergonomics of this model (versus my original vintage serial/PS2 Expert Mouse) have been totally fine for extended daily usage periods with my short fingers without the optional gel palm rest.The ball still floats nicely while still having good feedback beneath my fingers, literally feels just like my old vintage one, and without even loading the customizing software it does everything just as well as my old one always did, so well that I forget it's not my old one until my fingers happen to feel the new scroll ring that the older ones didn't have.The scroll ring was very crunchy and stiff and jerky while feeling a bit loose and wobbly and made noise at the two stiffest areas as I moved the ring but the more I use it the less stiff it has gotten and changing the windows mouse scroll rate setting has made the scroll ring's action totally predictable and considering the fact that the older ones didn't have any scroll wheel or scroll ring I'm happy to have gotten this capability added even if the quality of the mechanism for it isn't quite as nice as every other part of this very well performing unit.Some users have reported scroll ring failures within about 6 months with regular use. I haven't had mine that long yet but we'll see...Oh, and the scroll wheel DOES stay working when switching between 2 computers with the cheap iogear 2-port VGA/USB/Sound KVM switch so I'm just as happy with this new USB Expert Mouse as I've been with the vintage one I'd been using for over 20 years and wouldn't have replaced if I hadn't needed the "mouse" to be USB for my new KVM.Side note, the SlimBlade version is a similar size with all the same features but has different ergonomics and instead of spinning the scroll ring you twist the ball to scroll which sounded strange to me but after using the Expert Mouse's scroll ring the action seems like spinning the ball instead would basically have a similar overall feel and might resolve the crunchy sandy noisy scroll ring movement complaints that some users seem to be having with the Expert Mouse. I totally understand their point but considering that the older vintage models didn't even have a scroll uption besides programming the upper buttons to step the page up or down the less than perfect physical action feel/sound still makes for smooth consistent actual scrolling so just having that feature on a track ball is enough for me not to care about what I so far consider to be minor physical action issues that could use a bit of refining by Kensington but it does what it should for me so far so I'm happy.