They’re all the same; I don’t know why people agonise about choice of airline. It all comes down to your experience on the day; are there any delays and if so, how does the airline handle them? Next is the particular cabin crew member looking after your section and a whole lot of other things like the meal, the film, your neighbours and the seat.
What matters to me is schedules and timings; for a long-haul flight I like to sleep overnight and (with luck) wake up on the approach. If there’s a transit, I don’t want to be wasting hours at some ghastly dump like Heathrow and I don’t want to be doing an extra five-hour dogleg east to Dubai or Doha if I’m going to somewhere in Africa.
That said, I never use BA because they are more expensive than other airlines, their crew are more snotty and they played some really dirty tricks in the campaign against Virgin Atlantic.