If you just plan on playing RTS the important thing is finding a mouse that's comfortable to hold. You will adjust to the accuracy and sensitivity out of habit, so it's just the shape that will concern you.
If you're an FPS player on the other hand..
You have two options: A mouse with prediction and a mouse without prediction. Most pro FPS players (such as myself ) will go for an optical mouse (instead of laser mouse) without prediction to increase how exact the movement of the cursor is to your physical movement. Personally I turn prediction on though (Deathadder can turn it on and off) as it suits my play styles in my games.
I hope that helped. I use the 1st gen Razer Deathadder @ 900dpi 500Hz of polling. Won it at QuakeCon 2009 and it's still going strong now.
___________________________________ eLim | iNFENSUS eSports NA
[TheFavez] mOOnGLaDe, PiG, Nv
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