I fly this route every month, I choose BA for direct ex-EU solely on price. My personal preferance though is either QR or EK. That said I am in business so cannot comment on Economy or PE. just my observations here in economy the product gap closes so I would say BA if you want direct, EK if you want indirect to save a few bob. CX is always too expensive, i have flown their 777’s in economy in Asia and find the seats uncomfortable.