If you travel alone, Priority pass is a great deal. if you travel with a companion/workmate/other half, an airline club is usually better. PP charges for guests, which can add up.

The other thing you point out is diversity of airlines Do you know which places you go to most? Check out what lounges are there and decide.. I recently signed up for a World Club membership and changed over from PP due to the guest fees, plus 90% of where I fly have either a WC or a partner lounge that would take the WC card.