Some observations from me:
- Resolution seems to have no effect on performance for some reason.
- In singleplayer I can get 10/20/30 FPS while in multiplayer I get 35 FPS and higher values, which is good.
- In singleplayer game works similarly on lowest (everything scaled down) and highest details (everything maxed out, FPS are only slightly worse).
I see many similarities between ARMA 2 v. 1.11 and Iron Fron 1944 v. 1.60. I hope optimization will be priority, but I know developers will have their hands full with many bugs, so it's probably time to arm in patience.