I practically live online. I'm disabled, and have a powered recliner with my monitor on a swing arm over my lap. I use an ergo keyboard on my lap, and a trackball on the right chair arm. In my latest chair, the right chair arm contains a collapsible coffee table. I have my trackball, a Stream Deck, a ShuttleXpress for editing video, and a ham radio Morse Code key. There's a USB 3.1 unpowered hub on the back edge to support all of these devices. So space is at a premium.I used to be a solid supporter of the Logitech trackball products, but when I started getting pain in the hand from the flatter design of the Logitech, I switched to the Kensington Ergo-Fit because it's at a more natural angle for the hand. In that respect, this trackball is WONDERFUL. The repetitive stress is far less and I haven't had pain from the trackball since I got used to the Kensington. It also supports 2.4ghz AND Bluetooth connection, which is handy when your home radiates as much radio flux as a small star like mine does (two computer people in the same house, both of whom are ham radio operators == LOTS of RF!). There's a button on the bottom for ejecting the trackball so it can be cleaned, and to clean the bearings in the socket. This is very handy, as I had to use the back end of a Sharpie on the Logitech.You DO have to keep after the cleanliness of the trackball bearings and sensors inside the ball socket, but this is true of all trackballs. If they get gummed up with schmutz, or cat hair, or whatever, it'll be inaccurate and difficult to roll. So keep after it!Now to my only real complaint about the device: The left click button. On mine, it seems to have TWO click positions, a false "light strike" click, and the actual left click. If you tap it too lightly, it'll FEEL like you clicked it, but nothing will happen. You have to make sure you solidly click it past that false click to the actual click, which requires just a tad more force than the Logitech.You'll sometimes find that your point of aim swings ever so slightly when you do this stronger click, because your thumb twitches. If you're trying for tight accuracy, lift your thumb off the trackball BEFORE you do the left click, and it won't move that little bit. This is very important in things like graphics use and in gaming. Aiming in a game can easily be thrown off, which can be a bummer with a ranged attack. But if you get used to raising your thumb just a bit, the firm left click won't make the trackball twitch, and you'll be more accurate. I didn't notice this happening with the Logitech. I *might* have the DPI too high...I just thought of that, and will check it. IF anyone knows how to avoid this problem without retraining the thumb, I'd love to hear it.One more issue that isn't with the function of the trackball. The rubber grip strips on the bottom will eventually peel off. If you just stick them back down, they'll peel off within an hour, as the adhesive is already ruined. Two of them have already peeled off my Kensington, so I'll have to try some epoxy or something to stick them back down. It's not a high priority because I have a sheet of grippy shelf liner on the tabletop so things don't skitter around, but this could be a problem for those using it on a smooth tabletop with no traction. In the picture, you can see the strips stuck to a white box that lifts the Stream Deck up so it can be used by the trackball hand more easily. (Forgive the mess in the background. Again, disabled.)The extra buttons on the trackball are a wonderful addition. The forward/back buttons ahead of the left click button are great, and I use them all the time. I set the side buttons on the edge under the trackball to Enter and a couple of others that I forget. But having an Enter button on the trackball lets me copy, paste, and hit enter all from the trackball instead of having to tap Enter on my keyboard, taking my attention away from controlling the cursor. The scroll wheel is very well designed, and the left/right tilt switches on it give a little more control, especially in games, and the click down switch on the scroll wheel is perfectly placed for push-to-talk on voice apps.If you keep after the cleanliness, get used to the funky left-click switch, and the attendant possible thumb-twitch from it, this is an EXCELLENT trackball, and much better for the health of your wrist and carpal tunnel than the flatter Logitech device.