Regarding QF SIN lounge and BA CCR LHR, I don't think there's much competition.

Having said that, if we're comparing QF SIN lounge and BA CCR SIN, I can see why you'd prefer the QF option if you're after food. The food offering in the SIN CCR is worse than that in the main room, which isn't saying much, but I do like the much more intimate sofa+chair mini rooms in the SIN CCR for anything that the QF lounge can offer.

One other thing, the touch pad entry on the SIN CCR is rubbish, how that ever got accepted during snagging I'll never know.