Have to wonder how much the inconsistency just comes down to individual crew members motivation. I've had some great F experiences on BA but also my worst BA flight ever was in F. I'm not really demanding either as long as I have a decent flight. The BA F seat is more than comfortable enough for me. However the best F service I received was not from an experienced crew member (although I generally had really good service from experienced WW crew) but from a young MF FA who admitted to me that it was her first time working in F. It was a perfect F flight and also a full cabin so very impressive.