Pros: BA is the most reassuring airline service in the world. very predictable, punctual, comfortable seats and polite service.
very rarely do things go wrong.
Cons: the food in BA is consistently bad, at least for veggies.
the entertainment system is very old in terms of quality of picture and sound and the content of movies, etc. compared to the other airlines, including the European and American ones, the entertainment system is probably the worst one around