The x800 is a benchmarking card. The 6800 is a feature/enthusiast card. Both rock hardcore.
ATI takes the anti aliasing crown. Nvidia takes the OpenGL crown (Doom3 anyone
Since Nvidia opted to include Shader Model 3.0, they had to increase their die size to accomadate which hit performance by a bit. ATI will have to suffer the same fate next generation.
Also to dispell the myth, the 6800 does not require a 480w power supply. I have seen many benches that have run it on a 350w. Also, Nvidia released a statement saying that the only reason they suggested a 480w is that to do some serious OCing, you need that kind of power.
Also keep in mind that the benches you see now are with ATI's
final driver and Nvidia's
beta driver. I guess there is a problem with the way the Nvidia's drivers handle zbuffer that uneccesarily slows it down in dx9 games.
Lets also hope that ATI doesn't follow with what they did with a recent batch of cards. Evidently, there have been quite a few problems OCing them
The spinmeister has spun 8)
Since I am an avid OCer, 6800 all the way.