Just to bandwagon onto what 1Cajun said:
I sort of like flying in AvA, but I find myself avoiding it mostly now. I had alot of great fights in there. I like the AvA because I enjoy the planeset restrictions, and I like using it as a way to fly planes I will likely never fly in the MA arenas (like a zero for example).
But I find myself avoiding it mostly or the things that 1Cajun brings up. Not the HO's so much- I always assume I'm gonna get HO'd on a merge and avoid it. But rather, the engagement restrictions. The last time I flew in there, there were 8 or so folks on, maybe 10, and the fight was really moving back and forth. So, inevitably, you'd end up with several fights that degenerated into a 1v4 or 4v1, and then when the shot down guys re-upped the folks that originally had the advantage would get shot down one by one until they were the ones outnumbered. This more or less kept happening.
Or, as folks streamed into the fight, you'd have two guys going one v one on the deck in between the two fields. The guy losing would ask for help, a friendly would dive in, and then the guy who had the advantage would complain about getting ganged or ruining their 1v1, etc.
Ultimately, I found myself more worried about engagement ettiquette than actually just flying and fighting. There's always plenty of whining on 200 in the MA, but I was surprised at how much whining there was on 200 in AvA.
Like Dedalos said, there are plenty of arenas where one can fly with really no restrictions on how you play except those you impose upon yourself. While I enjoy the idea of AvA, I find the artificial parameters we impose in the name of fairness makes the whole experience less enjoyable.
This is really a 180 from how I felt a few months ago. I feel like AvA is really fun up to about 6 people (based on my limited experience). At 6, it's easy to keep tabs on each other and keep the fights balanced. Once you get above that, it seems like the stringing out of folks from the fights leads to numbers imbalances, and then it just becomes harder for me to figure out what everyone's going to think is 'fair' than just get into the furball and start shooting folks down.
Anyway, that's just my two cents. Having said all that, though, I'll still keep popping into AvA sometimes. There's so much I like about AvA over the MA, like the cool terrains, the clouds, the short radar ranges and vis ranges, etc. I really wish the AvA was the MA, and the LW MA was the arena that was always empty.