I can't speak for surround users but eyefinity works pretty much as good as origins.
All resolutions availble to me, with some surprising dx11 features that i didn't realise they had implemented.
All cinematics are confined to the centre screen also which personally i prefer.
One bug I've seen still from the original is that fire and such effects still distort character stood in front of it, any screenshot won't show this that I've tried though, either it's just hard to see from a still or these effects are applied in the frame buffer.
But the biggest flaw being, you can't see nor use any ability from your action bars when in surround..I'm hoping this is fixed in the retail
I didn't notice any objects being clipped on certain angles like origins either. Also with two 6970's the performance seems lacking alot. I assume CF isn't working at the moment.
Note: I didn't read the eyefinity links immediately but these screenies do help i guess.