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

First of all, I want to note that I bought this on sale for around $58. At that price, you cannot possibly do better than this trackball, and I own and use a LOT of trackballs. At its normal $99 price, I think you can get better value elsewhere unless you absolutely need a left handed or ambidextrous trackball.I am right handed, and use this on my left side to give my right hand a break and for when I'm just leaning back and scrolling through web pages or documents. For certain programs (editing in particular), I will swap this to my primary hand. Being ambidextrous was vital to me.Yes, the scroll ring on this trackball has a weird feeling. The other reviews are not lying to you. The ring has a little side to side give to it but I don't have a gritty feeling like others seem to have, rather a plastic on plastic rubbing sensation. It doesn't bother me in the slightest, but it might bother you.I don't agree with people saying the trackball is too high or the angle is weird. With the included palm/wrist rest, I find it to be perfect. If you are trying to manipulate this trackball with the tips of your fingers, you are going to be at a weird angle, but you're also not using the trackball correctly and will never be able to reach the buttons. If you're right handed, the base of your hand/palm should to be centered on the included rest, with your pointer finger resting on the top left button, your ring finger resting on the top right button and using those two fingers, in conjunction with your middle finger to manipulate the trackball.That brings us to the software and buttons themselves. The Kensington software is fantastic. It works perfectly on my Mac, whether I am on Bluetooth or USB (ignore the reviews saying the software won't work with Mac when on Bluetooth, that is no longer correct). You can adjust the buttons at both the global level and at the individual program level.All in all, you cannot possibly do better for the price at $58. For reference, I have an Elecom Huge, which I purchased heavily discounted, a Logitech MX Ergo (Plus version), Logitech M570 and a Logitech Performance MX optical mouse. The Logitech MX Ergo Plus is my primary right handed mouse with this Kensington on my left side, getting almost equal and often simultaneous use. Occasionally I'll go to the Elecom Huge on my right hand to get my thumb a break. The Logitech M570, which the Ergo Plus replaced, is my travel trackball as well as the trackball I'll use on the couch or in bed if I'm on the computer.If you're into trackballs and you can get this trackball at or around $60, it should be a no hesitation purchase.

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!

After having read several reviews around the web and being aware of the potential downsides as well as the upsides, I decided to buy myself one of these. Boy, am I glad I did. Admittedly, I'm the kind of person who's not satisfied with the typical mousing solution (I have really big hands and I do a lot of delicate work) and likes to try new things, so if that's not you then you may want to try one out before you buy if possible, or at least get one with a return policy. Caveat emptor. That being said, short of building a custom one myself, the Kensington Expert Mouse is pretty much what I want in a trackball, and having used it for awhile any regular mouse feels foreign and less-than-intuitive.First, the cons, in order of greatest to least issue (and they're all minor issues to me anyway).:: It does have a bit of a backward slope to it, probably about 10-15 degrees, which my large hands and already-tilted desk find mildly awkward. If you have a desk that's fairly high above your lap, then that backward slant will probably match the angle your arms are already at and this won't be an issue.:: The scroll wheel, as has been mentioned elsewhere, does feel a little scratchy, like a plastic-on-plastic sort of texture. It's not quite the buttery-smooth, gliding motion you expect after using the ball itself (more on that later) - it feels more like the back of a plastic spoon sliding across a Formica counter. That said, mine wasn't that bad, and probably would go away with a bit of silicone oil, but other reviews range from "not a problem at all" to "nasty-feeling deal breaker" so I suspect that Kensington's quality control could use a bit of tightening up. Again, get one with a return policy in case you don't like it. Common sense. I find myself using the scroll wheel less than I would otherwise anyway, as I've mapped one of the buttons to middle-click and I use that in web browsers to scroll up and down by moving the cursor. Smoother and easier than the scroll wheel.:: Occasionally, a button click won't register if you press the button on the corner or edge - you have to get closer to the middle. Rarely an issue unless I'm gaming, because my hands have a large span and I may physically miss the button at a critical moment when I'm not paying attention. It'll come with practice, I'm sure, just something to be aware of if you have palm-a-basketball-sized hands like me.Now, to the pros! Whee!:: Yes, it's got a pretty big footprint - it's about 5.5" by 9" with the included stiff-foam wrist rest (which I do recommend using, because of the aforementioned back angle) - but it doesn't move around. It takes up about 60% of the desk space that you'd dedicate to a typical mouse pad. Especially on those pull-out keyboard trays, there isn't enough room to use a mouse, but since the Kensington Expert trackball is under six inches wide it'll fit in a nice little rectangle next to the keyboard. Height is another matter, since the ball itself sticks out pretty high, but I don't personally find it to be too much of an issue. YMMV.:: The four large, programmable buttons. I'm not a lefty, but I mouse left-handed, so being able to map the buttons to essentially whatever I want with Kensington's free software is absolutely a blessing. In addition, different people will prefer to use different fingers for tasks of varying frequency, so whereas I don't right-click much and map it to where my ring finger sits, someone else may put it under their index finger or thumb. The software in general is pretty easy to use, and has enough functionality to feel nicely customizable without being so in-depth that only an advanced power user can take advantage of its potential.:: The trackball. Oh, that trackball. Smoother than a greased Fonzie on a Teflon-coated ice rink. Right out of the package it actually feels slightly rough or not as free-spinning, because the ball and its three contact points are completely pristine. Once you get some skin oils on it through use, it's like buttah. Gross-sounding, I know, but pretty much everything you touch gets skin oil on it. Speaking of which, the ball is just dropped into its socket, so to clean out the inevitable gunk that will accumulate in any trackball assembly you just have to turn it upside down and the ball falls out. No disassembly required. The inside of the socket is smooth plastic, so you just wipe it out and get back to work. The ball itself has a nice bit of weight to it, and is positively pleasurable to the hands in use. It's got a solid feel and has some inertia when you move it, which brings me to the next point...:: It has an infinite range of very smooth motion. I currently have a dual-monitor setup, and (besides being very awkward and un-ergonomic) I despise having to pick up a mouse, move it back to the other side of my mouse pad and continue my motion across the screen. DESPISSSSSE. It makes my fingers recoil just thinking about it... Ahem. Anyways. A quick flick of the ball will send the cursor moving across the screen, and the ball's inertia will continue the motion. It doesn't jump around or go crazy, it just follows the ball like it's supposed to. I have the acceleration parameter in the software set to maximum, so a fast motion of the ball will cover lots of ground quickly, but slow motions will still allow fine, precise positioning of the mouse. This becomes an even greater blessing with triple- or quad-monitor setups, and once again, this trackball takes up less desk space than an ordinary mouse. You don't have to have a huge screen to need this, either... for extra-fine work like Photoshop or video editing, you may want to slow the cursor speed down, which effectively makes the screen much larger relative to the motion of the mouse. There is no picking up and putting down with the Kensington Expert trackball - you just keep rolling. If you're not there yet... keep rolling. It feels natural, the way navigating a computer should.So, to sum it all up, I guess I could say that I love my Kensington Expert Mouse because it feels right. It's intuitive to use, customizable, ergonomic, and it just works. There are a couple little niggles, but in my humble opinion they are far outweighed by how they make my computing experience easier and more natural. Because everyone has different needs for their computing experience, not everyone will want or need one of these. If I was just an occasional casual computer user that isn't concerned with ergonomics or ease of use, I would absolutely think twice about spending $75 on a mouse I'm not sure I'll like when the one I have mostly does what I need it to. But that's probably not Kensington's primary market here. For me, and people like me, it's worth the money to make my interface with my computer feel good, because I use it every day.