I've flown both BA and QF on this route within the past 6 months, and prefer QF. But I haven't flown J recently (so my comments are based on the F service). Guy Betsy's summary is spot on, though BA seems to have finished its cycle of making the catering as bad as possible and is now improving once again; but the meals are still dismal compared to 2 years ago. I suppose the catering strike at LHR has had lasting affects. Luckily this is a JSA route, so QF and BA services at LHR are identical (so no difference in terms of ground facilities).