As HT wrote, SQ truly take care of paying F passengers. Singapore flagship lounge is among the best for both F and business class. I was PPS Solitaire member for about 5 years traveling mainly on business and occasional F through upgrade and I have acess to F lounge. However when for the first time, I was a paid F passenger in SQ, I was taken by a concierge right from check in desk through immigration (Changi has a special immigration desk for SQ F passengers) and to a special section in the F lounge that I never noticed during my earlier 30+ visit. It is secluded, peaceful, sit-in dining, order taken and fulfilled for all kind of demand.
That is I called a true F lounge experience. BA T5 F lounge expeiencebis no where near that.
I believe most F passengers (and many business passengers like me) are not so much worried about what food and drinks are available, unless he/she wants to sleep the whole journey, the main expectation is a peaceful place to rest before a long haul journey avoiding the chaos of the airport especially Heathrow.