I had a chat about this with CX at LHR recently; it seems loads out of LHR are very high on CX (despite CX now running 28 flights per week -- I was surprised to hear that; and NZ, QF, Oasis etc. starting HKG-LHR service). Business is booming, and they don't have to try very hard on this route to compete. There are something like 12 744/equivalent flights per day LHR-HKG (just Oneworld has 6x744 and 2x343/346 daily!).