Oh man, the DPI switching on the G500 is awesome for TF2. For Scout I made it hyper-sensitive and it's so much easier to follow people when you're running around in their face trying to blast them with the shotgun, with my old mouse I had to keep it low enough to still play the other classes and I couldn't keep them in sight as they tried to get away. Now I can spin fast enough to keep them in my sights, and then drop the DPI down a little ways for other characters. For Sniper I use a high setting while I'm running around or using secondary weapons and drop it down a bunch for smoother, more controlled sniping. No trouble with the side buttons so far (though I did have to tie them to keystrokes to get the game to utilize them), I'm using them for reloading and previous weapon (I hate how TF2 makes you click after scrolling to a weapon, and this fixes that nicely). I'll probably use them for knife and grenades in CoD. After a few hours, I'm very happy with my purchase.