I have access to both and practised alot on Realflight. It definitely has some perks here and there as I found that the heli bit is a bit better and much easier to use on realflight. BUT Realflight can't simulate 3d at all. I teach myself to fly 3D cause no one else here is doing it and RF didn't help me jack. I bought Afp this weekend and I gotta admit that if you download the right planes for it it's as true as it gets. If you can hover an OMP profile DOD in AFP i'll gladly shove my radio in your hands to hover my fun fly around a bit.

Just my 2cents.