Foxhound :
Funny, I had the same feeling. I only played like 30 minutes of ArmA2 with ACE but had the idea as well my game was smoother. I have to admit though the server I was on had grass disabled while many/most servers force grass on (and I really have no idea why as IMHO it sucks performance wise) and my system has troubles with grass..........don't ask me why I have no idea but i hate it.
Joker :
Tbh. Me and some other guys from R2.5 have noticed that we have had a FPS boost, not a decrease which is rather odd.
Lucky bastards!
I noticed about a 15 FPS decrease. Man...That sucks. I wish it gave me a performance boost. I really need it! And I wouldnt consider a 4870X2 a low end video card...
And the beta patch gives me a little error message so I cannot use it. I guess I'll be waiting for the Official 1.05 patch for that hopefully awesome FPS increase.
And I noticed the Weapon rest feature doesn't work for me if I got a team. If Im solo or not the squad leader, It works...Maybe this could be fixed..But ehh I'll just change the Key Bindings.