I did "some" testing...
Thing is offline and online are different. Offline a little stutter might be acceptable, online it's not.
I ran the full detail sliders, and it kept hitching when loading all the trees, so I slid it back to "around 3 miles" (which used to be the previous max distance). I put on all the details except shadows. Shadows reduced FPS pretty noticably.
On the other hand, I don't know how much FSAA I can get away with. It's got craploads of memory, but how fast it swaps things in and out -- eh, I dunno. HL2:Ep2 runs "okay" with all details maxed except aniso and FSAA, but dips below 30 fps in many places. Particles and smoke and such still seem to slow it down a little.
Problem is I don't have that many games to benchmark it on (most of mine are older). A benchmark like 3DMark wouldn't help too much, since it'll give me an arbitrary number. I don't benchmark all that often and it'll mean little to me.
So any thoughts or comments welcome. I imagine I can run most things, but if I were running FEAR2, would it be on minimum details? Or cranked?
EDIT: Gyrene, thanks for the comment. Funny that AH is so GPU intensive when cranked up nowadays. It's all the shadows and new terrains!