Just got back from two weeks in Spain. Priority Pass was the bomb. We used it in Barcelona, Palma de Mallorca, and Seville, and all three locations were clean, quiet, and much less crowded than both United's Polaris and Lufthansa's First Class lounges in Houston, Frankfort, Madrid, and Munich.

All three PP lounges had no lines, plenty of seating, handy outlets, and a fine selection of meals, snacks, and free beverages, including full bars.

The airline lounges were packed, with lines at the door that included people who didn't have status to get in but wanted to try to finesse or argue their way past the receptionists and didn't care there was a line (and, IMO, used the pressure of impatient people behind them as leverage). Inside, every seat was full (although turnover was fast, so we got our cramped seats quickly). Outlets were more scarce. The crowd made it noisy.

PP access was as easy as pulling up my card on the app, showing the QR code, and showing our two boarding passes. I have since ordered a second, free PP card for my AU wife, but it wasn't ever requested or necessary.

I'm now a big fan of Priority Pass.