I often go to PAH in Clifton Moor (York Area) and I thought they were great :-\
The local petshops keep the piggies in 120x60 cages, whereas in PAH they had a lovely nice run attached to that big house thing they live in. Yes, they were together with rabbits, but it was baby rabbits and baby guineas, so no huge ones in there, and enough space for them to get out of each others way if need be. they were very helpful when I was looking for a rabbit rescue to get a friend for my old rabbit Jam, and they dont sell buns and piggies together. Also that they have the piggie care books very obviously lying around near the actual pet area, and afaik they also had some basic care sheets for the different animals they sell in a leafletholder on the cage wall.
All the animals looked healthy and happy, the cages clean and tidy, and I was quite impressed, having only seen shops before that were alot worse...
Btw, I wouldnt buy from piggieshows or breeders either, you are still supporting that whole stupid cycle if you do.. there will always be people who have unwanted litter because they were too dumb to have their boar neutered so the rescues will always have plenty of piggies there, without us encouraging breeders to breed even more by buying from them. In my eyes thats just as bad as buying from petshops. They might be kept better there, but thats not the point, you are still supporting the wrong people. I'm for rescues all the way!