I am not enamoured with BA's showers at LHR arrivals. The 'wet room' design has to be one of the most stupid idea (at least as executed at LHR) I have come across in a lounge shower suite (and the suction noises are also unpleasant). Breakfast-wise, BA has hot food but the breads, viennoiseries and cold meats are nicer in AF arrivals at CDG.
I also agree with the point you made in an earlier point about the difficulty of comparison given the non-uniformity of product across the fleet. While I generally like the BA J product, IFE on non-AVOD equipped a/c is disappointing.
Also, some products which, in themselves, are a good idea can be executed badly: dinner in the lounge on BA sleeper services is great on paper but the food has become so dire (at least in J; I haven't experienced the F version) that it ruins the concept.