When I installed the second beta patch my fps went from 50-60 to 25-30.
Also when I installed the official patch it was still 25-30 fps and looked bad.
I changed the drivers and changed the resolution and wham 50-60 fps smoother than ever
maybe you were having the same glitch as me causing low fps.
I just tested the quick missions and they all run 60fps solid in most conditions. Game now runs better and smoother than IL2 46 ever did.
Also SLI seems to have improved too but still much smoother on a single card.