I noted above a 10 visit cap--which does not cause problems, since I rarely use PP lounges; In LAS the Centurion Lounge closes at 11 PM, down the corridor the PP (The Club) is open until 12:30 AM--convenient if I I'm taking a 1 AM redeye. The Centurion Lounge has hot food until 10 PM, they have at most 5 types of beer, while The Club has 8+ beers.
PS: Due to over crowding in the LAS Centurion lounge they removed a lot of soft chairs and replaced them with unpadded chairs...so at times the comfort of seating at PP can surpass Cent.