I am by no means an expert in airport lounges, but my experience with Priority Pass is that it sounds far better than it actually is.
It took about 3 weeks for my physical Priority pass card to arrive after I activated the benefit.
The main problem with using Priority Pass is simply finding a lounge that accepts it. Although they have a brochure, what you may not realize is that in a typical international airport there may, say, 10 lounges. Half of them do not accept Priority Pass. The rest are scattered among the terminals - and maybe not the terminal from which you are departing. A terminal that accepts PP may be on the other side of the airport. Further, it may be behind security, so you may not even be permitted to access it if it's in a different terminal. So you roll the dice and go to the other terminal to enjoy the lounge, hoping to get back in time to get through security and to your flight?
I highly recommend you get a free app called Lounge Buddy. In your profile you can tell it what credit cards you have and enter any airline programs where you have high status. And of course, there's a checkbox for Priority Pass as well. You can then enter your flight and based on the terminal where you will depart/arrive and the ticket type you are using it will let you know which lounges you can actually use - based on more than just Priority Pass. You will be very surprised to see how FEW lounges you can actually access. This app knows all the ridiculous rules and exclusions to accessing the lounges. As a for instance, I was flying out of LAX on a reward first class ticket and thought I could naturally use the airline's lounge even though they were not affiliated with Priority Pass. Turns out only international first class departing flights had access to the lounge. Lounge Buddy knew that. And even if a lounge is in the same terminal as you, you may be restricted based on the GATE from which you are departing. It's truly a maddening set of rules that seem to exist only to ensure few people use the lounge. With the Lounge Buddy app, you will know far ahead of time which lounges you can actually enter based on your travel itinerary (assuming they don't change your gate...). It also lets you know which lounges you can access through payment. I only read about Lounge Buddy through a travel blog; I'm sure it's one of a dozen similar apps.
I have been able to use an airport lounge exactly twice in my life. Both were because I had a first class reward ticket on United. It was really nice. I've checked the app for at least a dozen other flights and there were no accessible lounges that allowed access for Priority Pass. That was at some pretty huge airports: LAX, LAS, MCO, EWR. Sure, there were a lot of lounges that took PP, but not in my terminal.