LogitechMX Ergo Wireless Trackball Mouse, Ergonomic Design, Move Content Between 2 Windows and Apple Mac Computers (Bluetooth or USB), Rechargeable

This is a replacement for exactly the same trackball mouse I was using. The old one just started doing quirky things like automatically double clicking on something when I only wanted to click once or the pointer would drift around sometimes. I was thrilled to be able to replace it. I figured it would just be plug and play since I already had the USB dongle in place for the old mouse. Oddly, the new mouse didn't work with the old dongle. Once I installed the dongle that came along with the new mouse everything worked perfectly and all of my customized settings were in place. I highly recommend this mouse.

Edit: compared to the Ergo M575, this mouse must be cleaned more often. I have no idea why. The ball is more solid and smooth, but gets slowed up in a few days by debris. The cheaper mouse needs to be cleaned every couple weeks. I still like this mouse better.I got the less expensive Ergo M575 some weeks ago and liked the trackball experience so much I upgraded to this for my desktop. As the price reflects - it's a big improvement on the already great M575. There are only two things - you need a pen to pop out the trackball, and the palm part of the mouse feels a bit small - and I have small hands. It's by no means uncomfortable, but it doesn't fully cup your palm... on the upside, it's the size of a normal mouse as such, instead of the often chonky trackball setup.The plastic is very high quality - matte finish and slightly rubberized for grip. The adjustable stand (which has only two settings - tilt and none) is a solid piece of metal that stays put. The buttons are perfectly clicky, tactile and have a kind of "sharp" feedback if that makes sense. The scroll wheel is fine - the sideways click is nice, but it doesn't stand out as exceptional. The trackball is the real highlight, however, being perfectly smooth. The only use I can think of for the precision button is doing some sort of media work (dragging loops in an audio workstation, using a paint program or photoshop, ect.) because it slows the cursor down by what seems an order of magnitude. I don't think I'd use it outside of such, not even in a videogame. Maybe this can be changed in the software (see below). Battery life is decent too. It's the most expensive mouse I've owned - and the quality matches.The only real negative here is the garbage software. I just can't get it to run no matter what I do (I use linux and windows, but apparently the issue is even worse on mac). Forum posts suggest this has not been fixed for almost a year - though it inexplicably works for some no issues. Personally I don't really need to customize the mouse, however, it could be a big potential drawback.

This is about the sixth Logitech trackball I've bought, along with half a dozen keyboards, and it's among the best of their products. The M570 has been my favorite pointing device for years, and I've worn out a couple of them -- the L and R button switches take a lot of beating, L especially, and after a couple years the button becomes erratic. This, of course, is a terrible flaw, since it means you may accidentally DROP something that you're dragging across the desktop -- occasionally into some folder you didn't notice -- and then it's a challenge to find the file (or 100 files) you dropped.Logitech replaces these worn out trackballs for free, unless they last too long, and then I'm stuck buying a replacement. But they last for years, and the M570 is now less than $25, so it's not even $1/month "maintenance" cost.I mention the M570 reliability mainly because the new MX ERGO is reported to use button switches that are 10X longer-lived, or more. Since that was the only defect in the M570, that should mean the ERGO is pretty close to perfect. If it wears out in 20 years, I probably won't be around to care.Compared to the M570, the ERGO is heavier and I find it easier to keep in place on my desk. I love the sideways tilt feature, since I can use it lying flat for several hours, and then give my wrist some relief by switching to the more upright position, which allows the side of my hand to rest lightly on the desktop. It's also much easier to relax my fingers without inadvertently clicking L or R.I suppose if I were using this as a portable controller I might not like the extra weight, and I did often carry the M570 with me on trips. If I were doing that on a daily basis, in a briefcase or backpack, the added ounces and volume (the ERGO is about 20% larger) might be a problem. But the trade-off is that it stays put more easily, on a much larger and tackier rubber base layer, and it's more restful to use.I do miss the acceleration feature, long a standard among mice and trackballs, but the one-touch Hi-Res button somewhat makes up for it. I would prefer both, and I hope Logitech will reinstate acceleration in the next update of the new configuration utility.The little nubs that the ball rides on are seemingly indestructible. Some reviewers complain that they're plastic, but I believe they're actually a kind of ceramic or glass. Considering that my oldest M570 (5 years?) still runs smoothly and the little nubs are still round with no visible flat spots, I'd say they're considerably harder than most plastics, and I doubt they are plastic at all. Viewed at 30X they look like ceramic to me -- glossy and absolutely smooth and spherical. In any case, they afford very light, smooth rotation in all directions, and they don't wear out. Like any small mechanism in a hands-on application, they do collect dust and other debris from one's hands, but that accumulation of dust and furch just makes the ball movement gradually increase in friction. Pop out the ball, flick of the little dust donuts with your fingernail, and the thing is super smooth and free-wheeling again.If I could take off half a star for the lack of acceleration, I might do so, but in all honesty, I've been switching back and forth between an M570 and an ERGO for days now, and I can't say I notice any significant difference in pointer movement. On my 50" UHD monitor, it's a long way from one side to the other, but that's why I use a trackball in the first place -- I can just swipe it a few times at the medium-high speed setting, and I've traversed 3,840 horizontal pixels with barely any effort at all. In the end, if I had to trade the Hi-Res button for acceleration, I'd go with the button, and of course that's what you get with the ERGO.But all this is really nit-picking. The biggest bonus after comfort is the improved scroll wheel, which now has L and R tilt, in addition to downward clicking, and I've missed that for years using the M570. I do wish it had a few more buttons for less-frequent uses, but there's something to be said for simplicity -- I have a few other pointing devices with lots of buttons, and I was never able to make them indispensable.The biggest downside is the price. I'm not sure why this costs 4X the price of an M570. Clearly it's more expensive to manufacture, but not by that much, but then it's new, and the development costs haven't been amortized yet. If in a year or so it comes down to $39.95, I'd call it a bargain.

Love the mouse. I had a little older Logitech trackball and it was great but lacked the "flow control" feature. Since I have a PC and an iMac this was a great solution. I am able to use on both machines as described. It's comfortable to have my hand on for extended time. The buttons can be customized to your preferences example /copy and paste -my favorite as well as other actions. If your tired of moving the mouse and having it jitter on the mouse pad as they all do - this is the answer!Mouse has a battery but comes with a charging cable that had me scratching my head. Not sure about that yet but I'm sure it will work properly.Mouse was SUPER EASY to set up. Tons easier than other Logitech mice I've had. Recommend this mouse. You'll love it!