I've seen reviews showing the direct opposite, having 2-5 more FPS to their ATi equivalent. Overclockersclub reviews always have the NVIDIA cards outperforming the ATi 48xx easily. Maybe poorer systems don't benefit, but a souped up gaming computer with decent CPU/RAM speeds catapult the NVIDIA GPU more, leading to it smashing the ATi competition.

No idea, suffice to say, no review I've seen has shown the 48xx being superior.

As a side note, I just hooked up my GTX+ - SUCH a relief to have NVIDIA back. All the bugs I was having with dual monitor are instantly gone and BioShock 1.1 no longer crashes due to "ati".dll display driver failing. Incredibly, the NVIDIA display driver isn't failing where the ATi one did, hoorar.

EDIT: Maybe it's the resolutions you judge it on, I compare them on resolutions around 1600 / 22" monitor resolutions where the ATi cards don't do as well as their NVIDIA cousins.

http://www.legionhardware.com/document.php?id=755&p=0
http://www.techspot.com/review/103-asus-radeon-4850/page11.html
http://www.tweaktown.com/reviews/1539/
http://en.expreview.com/2008/06/24/first-review-hd-4870-and-hd-4850/21/

It is only when you turn AA and AF on that the 9800GTX falters. But would you purchase a $200 card and run games without AA and AF? You tell me...

From a critical point of view, yes I would, firstly as I don't consider that price range a high-end card nor an expensive item to purchase. Secondly, turning on AA offers very little visual improvement, so many people don't turn it on. My mates also don't run AA on a $200 card, they consider it pointless for various reasons, especially the minimal improvement point.

The only reason I personally run AA at max is because I just set all my games to 100% high settings for the hell of it and overclock my components to f***ery... because I can. =P

It is rather useless though, when I run on default medium or default high vs my 100% high settings, I can't really notice any difference. So this doesn't make it a problem for the NVIDIA cards.

EDIT: Also in that TechSpot review you linked... I looked at Crysis and World In Conflict... and the 9800 GTX+ smashed the HD4850 easily... and that's the comparison I'm making. 9800 GTX+ - HD4850. GTX 260 - HD4870.

AA is overrated, 9800GTX > HD48xx any day

HD 4870x2 is the most powerful card on the market now. nVidia will probably release something more powerful here soon, but for now the HD 4870x2 owns all. One caveat, it costs $550 dollars right now, so it is out of a lot of people's price range. The best card for the money I have seen is the 9800 GX2 on Newegg for about $260 after rebate that is factory OC'ed. This or two of the Zotac 8800GT's is what I want for a new build.