It depends what your looking for. ATI has better technology but nvidia seems to have better drivers. My next card will be one of the new ATI ones so I do hope that they improve their drivers. I mean come on ATI. 4.4 cats work with theif 3 why not the later ones? ATI seem to fix one thing in thier drivers but break something else. A graphics card is only as good as it's drivers no matter how good the hardware. It also seems to be a bad idea to buy new games when they first come out when you have an ATI card. Their cats normally seem to have one problem or another with them and they normally aint fixed until a couple of versions or more later (normally breaking another game in the proccess). I never seem to have problems like this with my TI 4600 on my 2nd pc. Nvidia's drivers always seem to work much better.
LOL. Didn't check the links at the top. Thought he was asking what the best cards were. Sorry about the rant. It felt good getting it out at the time but now feel a wee bitty daft. The girls look nice though.
Well regarding your point, I feel it is the other way around.
In this case ATI has the best drivers as the X800 is a supertweaked 9800.
Nvidia has brand new architecture and each driver set they release will boost the card.
Could be wrong, but thats the impression I get.