For anyone who is still reading this thread and who values sleep, BA's dinner service is in my experience usually much slower than AA (without any express alternative). On my Denver to LHR a couple days ago the dinner service actually took three hours (45 minutes just to serve the post-departure drink, after serving only water/juice pre-departure). Combined with the fact that BA starts breakfast two hours before landing, there was barely three hours of quiet time despite the long flight.