Interesting posts...and can't resist adding my tuppence on the subject. As a regular flier of both BA and CX, I would, on LON-HKG return, without question take CX. A few points:

-Crew really look after you on CX;
-food & wine infinitely better - grand cru, the best of the best;
-seat much more spacious than BA; and
-AVOD which has worked on 5 recent CX flights, sadly only exists on a few BA a/c
-Krug/Caviar service a wonderful touch of luxury on CX, reminds one that you are travelling in First Class;
-inflight service is quite elegant without being intrusive;
-The Shanghai Tang PJs are very comfortable and stylish;
-the lavs are always immaculate and well stocked with products.

I find that CX First passengers are treated with kid gloves...replete with easy check-in at both ends, the occasional escort to the aircraft, priority boarding that works (unlike BA, CX still use colour boarding passes so ground staff can spot you a mile away and ensure you never wait in a queue to board!), priority disembarkation, and First Class baggage that really does come off First (on a recent Dec flight, I had four bags and they were literally 1,2,3 & 4 on the carousel). The Wing and/or The Pier in HKG are superb lounges, with great dining options in either, divine shower rooms/relaxation spas, world-wide newspapers and magazines and lots of computer / work stations.

Sadly, many of these are missing from BA, with more cluttered seating, hit-or-miss service, food & wine that really needs a re-think (I know some F pax that are heading back to the Club Kitchen for snacks!), in-flight entertainment poor in comparison, service lacklustre and aircraft that are tired.

For £2800, go with CX...you'll love it!