Thanks for the feedback. Does that Kensington trackball work for gaming?
It's good for casual games (often more fun than with a mouse), fine for low to medium precision/reflex/speed games, horrible in high precision/reflex/speed games
Good: Asteroids, waves, geometry wars (any simple game with a small 2D playing space)
Fine: Team fortress 2, DotA, WoW (RPG games, casual shooters)
Horrible: Battlefield, Starcraft (competitive twitch reflex games)
I use it for the good and fine categories but switch to a mouse for the horrible.