QF F buffet selection is mostly nonexistent, or we have a different understanding of the word buffet. I mean it's just 6 boxes of mostly salty biscuits. I'd argue that the QF F lounge is mostly about the à la carte dining and the showers actually. The bar is also good.

Note that it opens at 14:30 which can be a problem for very long transits. But some people will doubtlessly argue that you should the city if you arrive earlier at SIN than that.