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

Great mouse, solid weight, software is a nice addition. Easy to connect using the usb A connecter. Swapping between USB A and bluetooth lets me swap between 2 different devices easily which is nice. Only downside is that the small usb does not have a storage place on the mouse so it is easy to lose/misplace.

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.

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.

Will never go back to a traditional mouse. This is my THIRD one!

TL;DR Decent improvement, especially considering the price has come down. It looks nice, the body is higher quality, but many of the new features have critical flaws. Still, best trackball on the market that I've found.I love the M570 trackball mouse from logitech. I've bought 2 of them, and recommend them to everyone, to an irritating amount I'm sure. So, I was excited when my friend linked me that the MX ERGO was coming out, since there don't seem to be any real competitors to the thumb-trackball design style. Sadly, there are many design features that I don't believe are helpful, or missed the mark. I will list them to excess below, since I just got annoyed due to #7 as the last straw, and decided to rant here, the only place anybody might read about, let alone find helpful, such minutia.The Good:0) The mouse itself looks very nice. Replacing the blue trackball with grey makes it appear much less tacky. And, the material the body is made of is softer, and lightly textured, with a rubbery feel, that prevents hand slipping (Except for the left and right click buttons, which are the familiar smooth plastic). Clearly a higher quality build, with attention to tactile sensation and practicality.1) It's very heavy, because of the new pad. One of the primary flaws with the M570 was the 4 little rubber feet on the bottom, that inevitably came unglued, and had to be re-improvised: so a full bottom, rubbery traction surface is very welcome. And it may be neat that it's magnetic, but the pad's weight is easily half or more of the whole mouse. What's more, you can remove this pad (again, it's magnetic), but you're just left with an awkward, round protrusion, which is impossible to balance on. I can't imagine using this mouse WITHOUT the pad, so making it removable doesn't seem useful in the least, except I suppose for removing and cleaning the trackball, which could have been accomplished with a button, or side access of some sort.2) Return of the forward and back keys, quite welcome, good placement. They're longer and shallower than before, and seem to make a little click each time you rub your finger across them, which is extremely minute, but an annoyance nonetheless. All mice should have these buttons.3) The scroll wheel. It's rubberized, with traction marks, to make it more reliable to roll, which is nice. It also has a left and right angling settings, purportedly for scrolling left and right via the wheel too. However, using these left or right scroll wheel clicks, WITHOUT also scrolling up or down somewhat, seems nigh impossible, and certainly isn't highly convenient. Most importantly, however, is that there is an excessive amount of slack on the normal scrolling function. It is extremely loud when it scrolls, and there are clicks during scrolling from the wheel, that don't actually register as scrolling on the computer, or likewise sometimes you can scroll on the computer, without having gone 1 full click on the wheel. I think the attempt at excess features baked into the scroll wheel has compromised precision for a key component of every mouse.The possibly neutral:1) Ball Inset. The ball on this one compared to the m570 appears to be slightly more recessed into the frame than previously. This may be good, to avoid it falling out with a simple bonk, but additionally, the hole underneath for access to remove the ball, is too tiny / too deep for a normal finger to reach through and poke out, for cleaning the rotation contacts from debris accumulation. I had to get a pencil to remove it, which is a small detail, but one more exercise in unnecessary added effort.2) Contours. There seem to be even more contours to support the shape of your hand with this model, specifically at the far edge, where your pinky would reside. However, as best I can tell when trying to fit my hand to the curves as seem to be intended, it ends up tilted about 15 degrees counterclockwise to where my hand would normally situate itself. This results in the ball being at the very tip of my thumb, which prevents me from being able to move up very far, before having to reset my thumb's position; I prefer the ball to rest under just about the midpoint of my thumb's tip and it's first joint, which might seem picky, but what kind of review writer would I be if I weren't?The Bad:1) The connections button. I don't know how many people need to rapidly, and often, switch which device their mouse is connected to, without using the provided dongle. This key takes center stage, right below the mouse wheel, with big 1 and 2 labels to make sure you know which device you're utilizing a connection for. This key alone is questionable on importance of including, but there's no way anybody needs it to be as readily accessible as under the scroll wheel. It should, at best, be out of the way, on the side somewhere, instead of in a prime real estate location. Worst yet, this button is not available for customization, so you can forget trying to remap something useful there.2) The new precision cursor speed button. I've had gaming mice, and having the ability to quickly switch from high speed to fine tuning is something I've missed sorely, so this should be a positive. However, the key is behind the trackball, making it extremely awkward to press, and requiring you to use the very thumb you need for mousing, adding a large delay, and a lot of excessive movement. It could have been almost anywhere, and it have been better placement. It also has a little light, to let you know you're in precision mode; I'm ambivalent towards this, since it would be hard to confuse which is which, due to the extreme slowness of it. Granted, I believe you can tune the ratio of the high and low speeds via the app, so this is adjustable as one may see fit.3) The angles for the new pad aren't quite right. Obviously this will vary with different people's geometry and preference, but I assumed before purchasing that there was some incremental adjustment method for angles BETWEEN 0 and 20 degrees, but it is binary one or the other. I stay in 20 degrees, since 0 feels more like negative 10 degrees, but I wish there was a way to tune the angle to closer to a 10 degree mark.4) The former spot for your own battery has been replaced with an integrated, rechargeable battery, with a forward usb port for charging. They claim it lasts for 4 months, but at that timescale, it's really beside the point, since that's basically never having to recharge. I always used my own rechargeable batteries, but this admittedly makes it that much simpler. If there become battery issues in the long run, then you'd have to replace the mouse instead of just the battery, but it's hard to imagine battery life for something so simple becoming an issue before any other of a number of factors would first.Note: Battery finally stopped holding charge, requiring me to buy a new one. Granted, it lasted 5 years, but if I could've changed the battery, I could've kept using the mouse for longer.