Thanks for the link Vartuoosi! I decided to buy Arma 3, and you're right, it has improved quite a bit. Character movement is a whole lot smoother than Arma 2, and the stance adjustments are a great feature. I have to say, I'm really liking it. The fixed wing flight model is still atrocious (I wouldn't expect DCS level FMs, but something that at least tries to address the basic physics of flight would be nice), but the choppers don't seem to be as bad; pretty similar to Arma 2 from what I remember.
Count me in for some co-op action with y'all, even though I can only probably play for an hour or so. Steam name is rambler. There's a few different ramblers, so look for the one that has an A-10 avatar.