I fought a long time trying to get AF working on my Windows 8.1 installation.
For me, everything "worked" but it had really bad performance and low/slow fps, even tho it shouldve been a breeze with the hardware. It was utterly unplayable and after some time i had to simply give up.
Now im running another setup under windows 7 and have a fully working AF installation as well as the latest BMS.
I like the simplicity of AF compared to BMS, its easier to learn, easier to get into and the campaign feel alot easier to get an overview of.
But that said, BMS is indeed superior in every way, and alot more immersive!
Aside from a few important aspects that one must adjust to when going from af to bms, its not at all overly complex as i had first suspected. At least not if your (like me) happy with flying standard missions and just enjoying the experience
Getting into the more advanced functions, well that will probably require a whole new level of studying and im not prepared to go there just yet.