High end graphics come at a huge price - AH gives very good immersion in the sim - clouds, aa, reasonable graphics and good gameplay go a long way.
FB is all peer to peer, most of the servers are invisible cockpit, low furballs with a kill, die, kill, die, kill, die from bases 3 minutes apart.
The VOW Virtual Online War is better but you wait like 30 mins between missions - tedious as hell.
FA has better graphics but the arena's are tiny - 3 fields apiece and the same map for the last year - gameplay is poor and even with high end graphics it lacks immersion.
FA's lag is terrible and you need a high end machine even to come close to it being playable.
If anyone finds a better mmog flight sim than AH let let me know but for now AH is top dog.