I was using an IntelliMouse 3.0 before, which MS calls 'the choice for gamers'. LMAO. I always liked MS mouse over any others, but Razer has my heart now. I just finished my first round of COD4 with this mouse and OMFG I pwnt with such ease and fluidity that it's silly. I take back what I said about a mouse not raising someone's K/D. A professional, accurate gaming mouse is worth the money and way better than a regular mouse. I'm convinced.