Overall I am happy with the initial performance of the mouse, but it has given me a few problems the longer I have had it. Advantages: Initially the trackball is smooth and works perfectly. It helped me a lot with the wrist pain that I had from my old mouse.

I prefer thumb trackballs over mice. I've used Logitech trackballs for more than 15 years. Unfortunately, the M570 is the best one currently available. I say that is unfortunate because while the M570 works fine, its ergonomic form is pretty terrible.

This is my third Ligitech trackball and the best so far. The ball is better supported making it easier to move with no drag. There are a few new features with this iteration that add value, like the ability to program the buttons to you liking. All in all a better product at a fantastic price.

Can't be used as a regular mouse to move on a mouse pad. Only the scroll wheel can be used for that. That is the biggest drawback. Wouldn't recommend to anybody.

I have been using a usb wired versions of this trackball for a number of years. I bought this as a replacement and there are some issues. After about an hour the mouse motion becomes jittery with a short delay.

The M570 retails for about $50 ( Amazon Link ) at the time of posting. For a trackball style input device, you'd be hard pressed to find another along these lines. With the improvement in technology such as the laser tracking, Logitech will probably continue to see people that love trackballs flock...

If you're a long time reader of VH, then you all know by now that I hate mice. Literally, I just don't use mice, I don't personally review mice, nor do I get excited by a mouse. I am however completely addicted to my thumb controlled trackball.