Review on ELECOM Protection Storage Trackball BMA XT2BK by Young Toulson

I finally found a left-handed Logitech M570. As long as the product can withstand heavy use, it's even better than the M570. It has horizontal scroll buttons that can be software remapped, it has a low/high DPI switch, a slow/fast mouse movement switch, and even an additional left-most button that's activated with your ring finger. The ergonomics lag a bit behind the M570, but I'm sure I'll get used to it. Ball motion isn't as smooth as the M570, but I'm sure it will improve as I wear it. Also, unlike the other review, the Mouse Assistant software is written in English. And it has most of the options you want. EDIT: After a few days of use, the ball seemed to get stuck in certain spots. I know from my M570 that the ball slows down as the bearings get dirty, but in this case it was different. In fact, a layer of dirt formed right where the top of the ball touched the plastic cover, so I had to scrape it off and the ball started moving smoothly again.