I'm not sure what to think about those reviews. If those 3DMark11 performance benchmarks are actual, I can smoke a a 7950 in the techspot review and a 7970 in the Hexus review with SLI'ed 460's. On Tom's review they must have run Unigine 2.5 at 2560x1600 resolution because I can get 73FPS @1920x1080 same settings on the rest.
kitguru did some '7850 cfx' (their samples of 7870+7850 cfx) benches. the reviewers states that the 7850 was overclocked to match the 7870's ... afaik the higher spec card scales down to the lower spec one and the combo works like 2x lower spec cards. their tests show that the 7850 cfx outperform gtx 590, 6990. 7770 cfx performs like 7970-7950.
it was saddening to see tom's 7850 sample acting badly.
i have been always buying amd cpu because of cheaper price and good multitasking support and gpu of nvidia in past but now im buying amd gpu because they uses less power and some are cheaper and gives good performance so for now amd is my choice because of this cards like hd 7870,hd 6870,hd 6950 which unlock shraders.
i have to listen to my brother cause he is elder to me.he likes nvidia and we were building our he bought gtx 580 cause it was the 'fastest single gpu on planet' a few months ago.but when(after release of 7970) i told him that 7970 beats gtx 580 then he told me-
'wait for nvidia,they will kick amd's but.t as they usually do'
i like nvidia now also more then amd because its my current gpu but now amd is offering better performance thats why and i have my nvidia from 2 years and i didnt get a single issues with it thats why i love nvidia products but i think i should also try amd let see how much performance does it gives.