i have the 518 and it's great. i just use it on the bare "wood" keyboard tray. sometimes it gets some crap on it and it feels real rough when moving it, but i just clean it off and it's works fine. oh yea, i don't even use 1600 dpi, it's too fast for me. i have it set somwhere around 800 i think. i just like the way the mouse feels.