For RSI purposes, both sides suck horribly but it helps to alternate. The idea of having a mouse or trackball off center is often a huge reason for the RSI in t

For RSI purposes, both sides suck horribly but it helps to alternate. The idea of having a mouse or trackball off center is often a huge reason for the RSI in the first place. And if one is concerned with RSI, simply using a mouse, even one of the more ergonomic ones is a bad idea due to the large amount of movement. Trackballs, trackpads, and other devices, especially if they can stay centered, IMO, are preferable. I really like the rollermouse, which despite its name, is not a mouse at all. If anything, switching hands constantly is the ideal and this allows that. The magic trackpad 2 from apple is not bad either, but takes a lot more work from the arms and fingers.