mlakrid, you're correct. I was not implying that I was getting those gains in real world tests, however I should have worded that better to get that point across.
Although, in some tests I have gained close to that much performance. In X3 for example which I just fired up last night before I went to bed. I used to get in the 25 - 35fps range, now with 16xAF and 4xAA on as well I get almost 200fps! So... I think it really depends on the game, but in reality this card really does almost deliver 300% over a 6800 GT. Also keep in mind, this card is three generations newer. I have gained significant amounts of performance at equal settings in other games too, for example Neverwinter Nights 2, I went from high teens low thirties to 60fps (vsync). That right there is a hefty increase, and with vsync enabled obviously it locks at my LCD refresh rate of 60hz.
My performance would be even higher if I had a Core 2 Duo system, for relativity people with C2D setups get closer to 20k in 3dmark 05. However you are correct, you need the entire pie to be able to enjoy it. I wouldnt even begin to think about purchasing one of these if you have a Athon 64 3500 or lower. Even then, you would be significantly CPU limited.