i run all of my games at 1024x768x32 with quincunx FSAA, 32 or 64 tap anisotropic, and everything turned to max. even RTCW multiplayer with a ton of action on the screen (including multiple airstrikes and a ton of guys) runs great at these settings. i never get slowdowns in games, and i'm extremely happy with the results. however, a friend of mine just got medal of honor, and he can't run 2x FSAA with anisotropic at decent frames with his radeon 8500 and athlon 1.33, where i can run the game great with quincunx and 32 tap aniso. maybe the supersampling that the 8500 uses takes too big of a hit compared to nVidia's multisampling *shrug*. the whole point of getting a fast card, imo, is to run the features, so use 'em if you've got em.
--jacob