Actually I have to quibble with your assertion about Ati. Their latest graphics cards kick Nvidia's ass all the way around the playground (dollar for dollar if you want to spend $600+ vs $300 for Ati Nvidia comes out ahead in MOST benchmarks). They are the 4850 and 4870...
This is why the ATI drivers have been failing WHQL testing and 90% of the game market focuses on designing games for NVidia since NVidia has Physx built in on their 8600 GT and newer cards where ATI you have to buy an NVidia Agia Physx card to get true physx off CPU in game (NVidia owns Agia)..
NVidia SLI is much more stable than ATI XFire... NVidia works with MS to develope for MS Operating system with both Motherboards and Graphics cards...
The only advantage ATI has had over NVidia was Open GL.. NVidia closed that gap 2 years ago and blew ATI out of the water.. NVidia is the only company currently making DirectX 11 video cards..
ATI has taken the fore front with their All-In-Wonder or their Tuner cards.. seeing as how NVidia doesn't do Tuners.. that is the only spot where ATI shines.. which makes competition for Hauppage.
Now If ATI/AMD ever got their act together and offered real customer support for their products on all Windows OS and all system configurations.. including getting WHQL with their AGP cards.. then I would tend to agree with you..
Example... Dizzy just got Radeon HD 2600 AGP card.. I installed it.. Fresh windows install.. ATI drivers caused system to crash just after start up.. this is drivers from disk.. Drivers not WHQL certified for AGP.. Downloaded latest drivers and purged old drivers from system, reinstalled drivers from download.. system crash after start up.. Drivers still not WHQL..
It was the Radeon CCC (Catalist Control Panel) causing incompatibilities with the AGP card slot, the CPU to PCI bridge which required special driver installation (CPU Standard PCI to PCI bridge drivers), 2 hotfixes from Microsoft, and a reinstall of the C++ 2005 and C++ 2008 runtime libraries before I could get his system stable under Windows XP SP 3.. and this was last week.
Every NVidia I have dealt with .. plug it in.. MS recognizes it right off the bat.. DL current drivers which are WHQL certified and system runs great.. no jumping through hoops..
and even with Dizzy's system.. the graphics are slugish with current configuration that prevents it from crashing.
So your argument is ATI is better.. I build computers for a living.. ATI/AMD are nothing but headaches currently.. especially under Vista and Windows 7... but becoming more and more of a pain under Win XP...
How many Drivers for ATI do you have to have to play your games?.. I needed 14 drivers to play 30 games with my Radeon X1300.. I only need the latest NVidia driver to play all my games..
So which is actually better? Take if from a system builder.. NVidia is way much better in ease of use, capabilities, compatibility, drivers, rendering, DirectX compliance, Open GL..
instead of going with Biased reviews.. take it from someone who builds power and gaming PCs.