I am very anti-BA but I have to be fair. A few years ago I sent my son on a return trip, two sectors each way, on BA, and the way it was handled, from beginning to end, was outstanding.
I would go for a nonstop flight if you can so CX, VS or BA (off the top of my head I think they're the only ones that do HKG LON nonstop)
I'm surprised at the negative comment regarding KL, an ialrine I've only ever had good experiences with, but then I rather like the cloggies!