My #1 box has a BartonM @2.4gig / 512mb mem/ 6800Ultra / 1280x960 4xAA and a mix of Medium/High textures, with only a couple of setting on High actually. My low ram count keeps me from runninig all at High.
I can forget all settings high due to the unbearable stuttering with 512mb of system mem. But with mu current settings, after I first spawn at the biginning of the first game, the stuttering goes away and I don't seem to have a real problem after that. A day or so ago I was 117 kills with 18 deaths in a 64 person server with a 120ping, so it can't be that bad with 512mb mem.