I used a trackball similar to the one you linked for years. Ended up stopping due to feeling pain just in my thumb, and switched to various mice. After a few years, the mouse was causing some pain too, so I switched to the trackpad, and the ability to use either left or right hand.

Being ambidextrous here may help, as Mark has more definitively pointed out. The reason I went from mouse to trackpad was due to having a right hand only mouse, and an OS that gained gesture support.