I play games like Aion etc which are more demanding on full settings, and it's also known that crossfire setups with the 5xxx series in Aion have issues and dont even work, so getting a 6xxx series card is a great single card option for me, and as I play games (and mine during any afk time), I will make profits to buy even another card. This will net ~750Mhash/s, AND double as a sick gaming rig AND ALSO retain a lot of it's value if I ever needed to sell out.
Yesiree. I bought a second 5770 to xfire and it works fabulous (works perfect in all games I've tried). I have aggressive miners, and then mine while gaming with non-aggressive miners. In just two weeks I'm well ahead - even if bitcoins lost all value tomorrow. Winning.
Still can't play Crysis though.