Double the synthetic performance in many areas! All it took was twice the transistors and double the power to make it happen, too. Oh wait, it doesn't seem like that big of an improvement anymore, does it? Its real-world game performance doesn't match up to its synthetic performance, but it still eats up slightly over 2x the power.
I'll wait for R600. It's already in production and will be for sale early next year. Of course, we won't have any DX10 games until late spring or summer of 2007. Nevermind that fact.