>>105797199 (OP)bought one to nurse a strained wrist, as good as a regular mouse for most things ,only annoyance is that you have to clean them often as dead skin will build up on the points of contact, i would say precision can probably be better than a regular mouse , but it greatly depends on how much friction the trackball has, getting oen with ball bearings rather than slip pads is a good idea.
I also feel you probably could learn to use it for games, but the motion is different and you could probably leanr some different teicks to take advantage of having infinite camera rotation and momentum.