I do have PP via my Amex Platinum.

I am in Europe and there are some good PP lounges (VIE / MUC / IST / SZG as an example; LGW and LHR T2 are also not too bad) but mostly I use the Platinum for LH or DL SkyClubs.

Following an PP forum on FB, it seems that PP is often not useful when flying in the US (not accepted or overcrowded so PP members need to stay out). Most probably I would get myself a PP if I would fly the likes of Easyjet or Ryanair)