If you like ground War, you should go for WW2OL, it's very good in there but you need a VERY SUPER good System to play it. FM in there has got no E loss.
If you wanna fly, wich is why most of us are here, I sugest AH. WB seam to have a better FM in some ways (planes seam to be more willing to hammerhead instead of rolling into a "controlled" spin) but overall AH Flight Modell is better, planes respond faster and it doesn't, as some guy put it a while back, feel like there are rubber bands attached to the ailerons.
WB3 has still got a pretty long way to go, AH is getting trains etc now, more planes and I belive (not sure) improved graphics and effects.
Go with AH