Wow that 6800 is basically the 6600GT with double the RAM and a slower clock speed. Thats really weird. I dont know what i would go with. If you can overclock the 6800's CPU clock to match that of the 6600GT i would go with that. Otherwise i would probably just go with the 6600GT since they are the same amount of pixel pipelines. Although that 6800 is one badass looking card.