I am from NYC and travel almost exclusively with oneworld airlines.

Unless I've been wrong for a long time, you can not earn regular or base miles for your AA account on BA transatlantic flights. I would rather fly BA JFK-LHR (better service, in my opinion), but that wouldn't go towards my ExecPlatinum status. So, I'm stuck with AA to London.

I haven't done this, but when connecting to another European city from LHR, it seems like more of a pain to transfer from AA to BA rather than just BA to BA. One or two times I had to connect in LHR, I just screwed the miles and flew BA the entire way.

Now that Finnair is in the oneworld boat, I could fly that to HEL and connect to the other European city (you can earn AA miles on Finnair, right?). I hope Swissair joins oneworld, because that would open up even more oneworld possibilites in Europe. What about Aer Lingus?

I think that AA should cut all flights into LHR, get slots at LGW, fly there, and place their code on all BA flights. Then all of us poor AA flyers can finally earn BA miles transatlantic! But that doesn't look it is happening fast. Maybe I should see what Star has to offer?

Looking forward to hearing your opinions,
Flyer