I can play with DirectX 10, all settings High with 2x AA, no problems. I have no idea what the actual FPS is, but the only time it's not perfectly smooth is when I move my head around really fast... feels like it's over 30 FPS at least.
One weird issue is after playing for a long time, sometimes it will start stuttering. I'm not sure why, but I suspect it has to do with excess heat? I don't know much about computers, but it seems to be kicking out a LOT of heat, compared to my last laptop. Then again, the bottom stays relatively cool, so it seems like it's doing a good job removing most of it through the fan.
The screen sucks though, and the contrast is awful, which makes playing at night (in the game) much harder than on my last laptop... but my last laptop had a premium anti-glare screen. Now I wish I had spent the extra money and gotten the 1080p screen, but then again, pushing those extra pixels might slow everything down.... Decisions, decisions.
I forgot to mention I upgraded the stock memory to 8Gb @ 1600MHz, so that might make a difference. And all performance described above was with only the 6750M enabled, since Crossfire seems to make things worse. I updated my drivers with whatever ATI has on their website, but maybe I'm missing some special Crossfire driver?