I'm assuming it's around the weight of the mx700 so I'm gonna say no, if anything I feel more precise in FPSes with this weight in the mouse than with a regular batteryless mouse.
I'm just waiting for my current mouse to break down so I can get a really slick one. Then again, I've had this one for five years and it still works perfectly.
(actually it's the one with a button on both sides, not two on the left side)
God BLESS ball-less mice....greatest invention since the air conditioner.