The worst part about all these "ergo" mice (i've tried a lot of them) is that if your used to high end mice these ergo mice are nothing but an ergonomic plastic shell with $3 mice innards. The sensors on these mice are horrible and it made me crazy using these evolucent and other "ergo" mice. Low dpi, bad tracking, lag... This is for gaming, this is just how sluggish these mice felt, high dpi is not only for gaming, if i want to go from the left side of the screen to the right side with a 24' in monitor, thats not going to happen with these cheap ergo mice, your gonna have to pick up the mouse or something to make them move that far a distance.