1) I happen to prefer real results to canned benchmarks, and if you check [H]'s reviews the 5850 actually WINS in performance
I'll take canned benchmarks any day over "real results". Canned benchmarks are chosen by the developers to represent how the game will play overall. They are always the same with no variables. I much prefer that over someone just running around for 10 minutes. There are way too many variables to fairly compare 2 cards in "real results" for me. For example in metro 2033 there are some areas where just looking two inches higher towards the open sky will drop down 6-7 frames compared to if a player looks dead ahead. Am I suppose to believe the player was able to retrace his steps 100% right down to the camera position through each play through?
2) Even other canned sites disagree with that: http://techpowerup.com/reviews/Palit/GeForce_GTX_470_Dual/29.html
There is less than a 10% performance difference at all resolutions, and at 2560x1600 it drops to 1%. 20%? Not a chance.
Nice one using an article from May. Its not 20% but it is a very consistent 10% right now. Here is the latest chart from them showing a 9%-13% difference between the 2 cards at every resolution. Strangely enough there is now a 13% gap for your 2560x1600 resolution. http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTS_450_SLI/23.html Magic drivers? Maybe not but a definite improvement.
3) You want to talk about the effect of new drivers and then link to a review using old drivers for the ATI cards? Nice, real nice. But for what it's worth, [H] did a comparison of Fermi's new drivers vs. the launch ones: http://hardocp.com/article/2010/06/16/nvidia_forceware_25721_driver_performance/1 Outside of a couple of specific scenarios, the overall performance improvement was 1 or 2%, it didn't change anything.
Pretty nice yourself since the article you linked to is 2-3 driver versions old.