I have the Razer mouse too, it's excellent for having extra functions under your hand. I've got things like copy, paste, and browser refresh programed into mine. I don't do a whole lot of gaming with it, but when I do it is very smooth.
Expensive, but I was looking for something that would last me a good while. So far I think I've had it about a year, no problems.
I just gotta remember to keep the darn thing clean.