BA and AA programs are quite different.
BA charges per segment based on distance and class.
AA charges per zone.
Agreed. I would never use BA points for PEK-MCO (or similar) even though I have a lot because the segment by segment pricing is a killer.
AA/CX via HKG is my general my preference (if I have time enough to kill to spend a night in HK in order to justify the serious backtracking). My second choice is JL, but this almost always entails an overnight in NRT (when going to the east coast). I really dislike AA between PEK and ORD (early morning departure and you have to endure AA).