iMouse T40 Wireless Ergonomic Finger Trackball Mouse with Nano USB Receiver, Programmable 7 Button Design, and 5 Level DPI Switch, for Left and Right Hand

I was a bit disappointed with this mouse.It’s difficult to get the cursor to go exactly where you want it as it tends to wander around the point your trying to click.The software provided for it just conflicts with Windows settings, I was constantly up having to go back into settings and reset everything the way I wanted it.I eventually deleted the manufacturer’s software and stuck with Windows settings. At least I’m able to use it but I have to go back to my old wired trackball mouse if I’m doing anything that requires more a accuracy.

I thought this would make a suitable replacement for my Logitech Trackman Marble, which is now out of production and very difficult to find. I've never been 100% satisfied with the Kensington mice as there is something about them that just doesn't feel right - it might be the profile of the base not being steep enough. I thought this would improve on the Logitech because it adds in a scroll wheel. The build quality feels good, and the extra buttons are somewhat needed, but the placement is just so god awful you can't use the scroll wheel without either completely removing your hand from the mouse, or grazing the buttons near the bottom as well.The worst part though, is the motion of the mouse. the Y axis is fast, the X axis is slow, so it feels just awful to use. Moving the pointer shouldn't feel like I'm trying to play pool on a tiny boat in the middle of a hurricane. This mouse is just plain awful.

I've wanted a trackball mouse for a while but could not find one that had the centre mounted ball with scroll and back and forth buttons. I finally came upon this mouse and it checked every single one of my boxes. Service was fast too. The only thing that I wasn't expecting was that with the scroll wheel behind the ball, I have to move either my finger down or my thumb across to use it. I think I would have preferred a design where the scroll wheel is in front of the ball so that I just have to stretch my middle finger up to use. Small detail, but it's something you would not think about before using it.

I did try to get used to it during 2 weeks. But no luck. I installed the software and set it up and it became better. But ... I just can not use it as a trackball mouse.It just do not want to move to exactly same place and direction to which I scroll the ball. It is a miracle how they made it. I initially read the comments about problems with cursor movements, but I was not even able to imagine how bad it is :(So I returned back to my old marble trackball with right button pressed not every time ;-)But at least the cursor moves where I want it to be moved. And what is important it stops where I want it to stop.On the Adesso trackball it moves where it wants to move by itself (+-15% of the direction I move it to) and stops where it want to stop (+- 20px from the position I stop the ball ;-)So I really do not suggest this trackball mouse. Waste of money unfortunately.I wish they make the second version of this mouse with normal cursor positioning.

I've used a Logitech trackball for decades and had qualms about this, but it's worked out, and the scroll button is nice. The only nit is that, unlike the Logitech, the back and forward buttons are too prominent and easy to hit when not wanted. Battery life seems reasonable; I'm still on the original set