My bro is using his Razer Death Adder on his mac and it's TERRIBLE! It moves faster in the Y direction than any other, when he makes large movements the mouse races across the screen but if he moves at a normal speed the mouse crawls across the screen at an unusably slow rate. He has turned the mouse sensitivity almost all of the way up but the movement discrepency has stayed. It is so bad I was unable to even navigate the OS to use the internet before I gave up. Have any of you used the Razer Pro v1.6? It seems to be Razer's only Mac-compatible mouse. Note, his mac is doing the same thing with a vanilla Microsoft Intellipoint mouse.