The BA SFO F lounge is (as said) quite small. It seems full even if only half the seats are occupied. It is not really a place to stretch out and while away a few hours in a daze of pleasure (as you can do in LHR T5 F Terraces or SYD QF F T1 lounge). The wide open space of the concourse often provides more relaxation with window shopping and just wandering with the occasional pop into the lounge for a "top-up" with your favourite beverage.