Error: Dell.
I'm pretty sure HL2 and CSS (Source) games are pretty processor/ram limited so keep that in mind when you test it out. My brother came up today and we played with his new GTS for a while, gets a little better framerates on those but still "slow" for 8 series standards. That, and you see huge gains in framerates from just increasing FSB and not much with GPU OC's.
Call of Duty 2 though, maxed out it ran PERFECT, silky smooth, No frameskips, and it seemed the GPU wasn't even trying.
I guess AA16 is pretty much overkill and I didnt see a difference with AA at 8.