I'm in my third year on Priority Pass and am very happy with it. (Do a search on PriorityPass; you'll undoubtedly find other threads.)
I don't have lounge access otherwise; not high enough in Elite programs and don't qualify for the AE Centurion Card. We've used it all over Europe as well as in the US; never a problem, never any different treatment because we didn't have regular lounge membership.
Do make sure the airports you use frequently have lounges you can use. Last I checked, there were none in SLC, CLT, CVG and some other major hubs. It may also be useless if the only one you can use is in a different terminal and you have to go through Security again to get to your flight.
There's no pattern as to which lounges accept it; it may be the President's Club in one airpot, the Crown Room in another. In some airports there may be 3 President's Clubs but only one takes PP.
We have an individual membership because I travel on business but my husband doesn't; I get the 10-pass package at $249 and pay $24 extra when he comes in. To us, it's well worth it.