You don't mention timings but the A350 is BA7 at 09:10 which I imagine requires an overnight stay at Heathrow. The BA7 is at 13:00 so much easier for a same day connection and arrives in Tokyo at a more sensible time (IMO). That is currently a 787 which would certainly have the previous generation of Club seating - yin-yang. Opinions differ but most prefer the Club suites.