When AW was killed, I tried Fighter Ace, Warbirds, and Aces High.
FA was full of arcade type play, the flight model was terrible, and the community was worst. Asking questions in there got you either trash answers, or no comment at all, not very helpful.
Warbirds while better, was in trouble management wise and a lot of things were promised. Community was better, but numbers were much lower than I was use to in AW, fights harder to come by. WB at this time is loosing players by the truck loads due to lack of the promises being for filled.
AH on the other hand inherited a good number of people from AW which basically brought the community with them. Hitech continually updates the game with two major releases a year (or there abouts), and has been building a new game called Combat tour where you will creat a player and through filling mission objectives will rise in rank through the war. AH has a big learning curve, but a lot of great sticks that will take the time to work with your to help you along (all volunteers by the way).
Aces High is by far the best of the bunch, but its your choice.