Gatwick is a holiday airport - as the vogue for premium leisure has taken hold, the pay lounges are very busy indeed as bought as an add-on, and best avoided. You also have to queue for drinks at a bar and generally it's not a leisurely environment especially if there's a stag party crowd in there. Similarly fast track is often clogged with people paying the extra and standard security is a better bet. Gatwick does security really well.

Best value in Gatwick South using a Priority Pass is the Grain Store (left turn out of the secret tunnel on the left as you exit security and the mortals go down the escalators to the duty free maze), where you get a £15 credit, enough for a "no frills breakfast" which is pretty substantial and better than anything in either BA lounge. The joy of having hot hash-browns instead of the tepid rubbery lounge ones is ineffable. With a coffee you'll be just over the £15, but well worth it. This is my go to place when not on BA, and sometimes even when on BA. If you have Amex Platinum it's almost a no-brainer if you want breakfast.

The two BA lounges are lovely, the business one if anything a little smarter than the Flounge. Food is ok, it's replenished regularly, and the staff are lovely. Great views of the gates and runway (especially from the Flounge) and I never mind spending time there.