I have enjoyed both for more than year now. Over that period, one or the other has had material I find more interesting, and I'd miss either one if it were gone. It seems that AA has become a little more fragmented, or "clique-ish", of late, e.g. the American Trad thing. And the whole WASP thing over there has left a bit of sour taste in my mouth since it smacks of elitism. But I'm sensitive that way. SF seems a little more laid back, down to earth, and has a better sense of community, at least for now.