Edinburgh is awful these days - I cannot see how the airport management don't wish to sort it out. There is no air conditioning upstairs, the place is so hot and humid. There are no seats, even in the eating establishments and you queue everywhere; car park, check-in, security, cafes and boarding.
I'm based in EDI and it is the worst airport I fly into or out of. Lack of stands means frequent waiting after landing, then when you get a stand there is normally a wait for guidance, then a wait for staff as the stand was a change from planned. Then when ready to go you queue on the way to the runway after being stuck in the cul-de-sac beforehand. ATC do a great job of trying to keep things moving but there are simply more aircraft than the place and cope with. The airport management have done a wonderful job of attracting new routes, the selection from Edinburgh is excellent these days but the experience passengers receive due to poor infrastructure is appalling.