My big questions is what's your budget, or are you getting one of those cards for free? If you're buying them, and your budget is $200, why not the HD4850 or a newer generation Nvidia card, like the GTS250?
my mate has an 8800gt 256 and i have the 8800gts. i was considering doing a swap with him if it was better for me because his pc only has a p4 and 1.5gb of very slow ram. the change in gpu for him wouldnt have affected his performance where as because my pc is more up to date, i was wondering if the gt would perform better. i dont want to but a new card because the 8800gts runs everything fine apart from crysis which i dont play much. i only really play l4d and wic which my card runs fine.