first person shooters? Razor... Wow? Logitech :P
It all depends on what you need.
If your looking for fast gameplay and very precise movements, go for the razor. it has 3500dpi and alot of superpolling. Razor makes the best IMHO fps mouses on the market. After owning 4 of them, i'm never turning back.
If you need macro's and alot of extra funtion buttons, i would definitely get the logitech. With more buttons that you will even remember, I'm sure you could just play entirely on your mouse when your left hand starts hurting after a while
But overall, I would choose the Razor. It is more sensitive, just enough to make that quick 2 milisecond adjustment. And if it is too fast for you, you can always change the dpi with the drivers. also it has a blue glow to it
. But the choice is yours my brotha.
Also, i know I spell razer wrong. I just like the way to spell it as Razor.