I actually just purchased the Naga last week and let me tell you...best investment for gaming ever! You can adjust it to pretty much any mouse speed, it's super comfortable, and it freakin' lights up!
Now let me say I was average before buying this mouse, now I'm pretty much top 3 PvP and in PvE monsters don't stand a chance. It took me about a day to get used to now I have 1-12 down and working on Shift+1-12. Pretty much all my commands are bound to the mouse.
SOOO WORTH IT! Improved my gaming experience and speed, and it's just an awesome mouse to begin with.
Edit: Also, super easy to set up ^_^