Not sure what you mean by that. Or why you're bringing the GTX570 into the conversation. It's a higher specification card and irrelevant to this disucssion.
How am I supposed to do that, exactly? Read their minds? Ninja into their offices and steal the secret memo's that say "always paint AMD graphics cards in as poor a light as possible!"? Or do you want me to join in your little game of conspiracies and speculation, rather than make comments based on the evidence available to me? Sorry CAT, but that's not my game.
I'm not questioning whether some review sites are biased one way or the other, I'm making a series of statements about the relative value of the two cards based on reviews from a site that I, personally, trust to be impartial, and my own research on availability and pricing.
As always, I would never advise buying any component based on the possibility of extracting more than stock performance out of it. And BIOS flashing is an even more technical activity than overclocking a graphics card.
I've been making my comments very specifically about unmodified retail-available cards, as that's what the majority of PC Gamers (rather than members of this forum) will be interested in, and that's the only level of performance you can actually guarantee. Overclocking and unlocking are nice extras, but I'd never give buying advice based on them.