Why not have your cake AND eat it too? I am currently using the Logitech MX Duo (which includes the wireless MX700 optical mouse, and wireless keyboard), and I must say, the gaming response is fantastic. I'm playing Doom 3, Far Cry, Halo, Half-Life2, UT2004, Call Of Duty, with no lag problems whatsoever. I'm also using them with rechargeable NiMh batteries. The ones I put in the keyboard have been in there since November, and yes, I play PC games a LOT, and the mouse has its own recharging cradle.
Go with the MX Duo, you won't regret it