Perhaps the T5 lounge complexes are a microcosm of the UK itself. The North is less populous, smaller, and thus a bit friendlier. The South is busier and it’s where all the real money tends to hang out, but it's a bit snootier as a result. And perhaps most poignantly, between the two, there’s f*ck all worth seeing
Interesting idea. So T5B could be Calais via the Shuttle then !
Out of the two A lounges, I would go for the North one for a shorter visit (much easier access) and the South one for a longer one (larger area to explore.....)