I don't like QR's scheduling, as it's two short-ish flights (6:40 followed by 7:30 block times, less in the air) so you can't get an uninterrupted full night of sleep.

CX is the way to go IMHO. And LHR-HKG is blocked at a blissful 11:40. However, I have not had the pleasure to try MH yet; flying on a 388 is very attractive (less physically draining than other aircraft=arrive more productive, for work or leisure, and less jet-lagged), as is the 12:25 block time.