Skuzzy's suggestions have been pretty helpful for me so far. Like he has said, there are areas where performance is gonna suffer (paraphrased). I saw some improvement in performance when I updated video driver. Note, after updating either the drivers or the patches for the game itself, there was much trial and error (and mostly error).
This is what has worked for my POS:
Turned Antialiasing and Anistrophic Filtering off or very low (offset stairstep by trying the highest resolution with desired performance possible - trial and error) Result framerate boost back to normal except when @ 400 away from contact (frustrating stutters).
Next, Turned off custom skins, weapons effects, and vehicles effects (do this by checking the appropriate disable boxes under Graphics Detail from clipboard). Also, turned both detail sliders to performance unless bombing where long range visability of target is needed. Result was good framerate and stutters disappear.
This is where Skuzzy and I don't totally agree. When detail sliders are higher, as needed in bombing, "Rubber Bullets" appear or should I say disappear. I believe Skuzzy explains this as packet loss. It is best to keep all sliders to the right unless you aim is good enough to hit something farther than .5 miles away.
I forgot to mention, that I turn all the background processes off using FSAutoStart before running AH2.
