I've got the same vid card and it's smooth as silk.
Granted, I've got a gig of ram, and an Athlon 64 3000+ CPU.
I tend to turn off AA whenever I can in games, anyway.
I still say, that's a fine graphics card. But I agree about getting more system ram. 512 really just isn't enough anymore, and you'd be surprised what more ram will do for you. Don't ditch the card, get more ram.