I have not flown on BA since the 1980's (never had to head that way), but I am told that today BA has a top notch Business Class product, having opted against the herringbone configuration or 'coffin class' that CX have installed.
In any case, there are plenty of other ways to get from HKG to LHR/LGW, such as CX, NZ, QF, VS (okay, not much better than BA), KL, EK/AY (as suggested above), SQ, etc.