IAD is lounge heaven! If flying AS (and depending on time of day), you can get into VS, AF, TK lounges. But better than all of these is the new Capital One Lounge, just after security. The service and food were exemplary.

I enjoyed my time in the AF lounge. Good food, plenty of space, lots of light, nice people.

The TK lounge is good if it's not overcrowded. But, every single time I've been there in the last two years, it's been packed with people. The food is good, but it's not worth fighting for a seat, IMHO. I'd rather just eat something in the terminal. YMMV.

Anyway, I think IAD is one of the best, if not the best, domestic airports for PP members - lots of good options.