The smaller AA ones at PHL/DFW/SFO/PHX are okay. BOS you gotta be lucky, JFK/MIA and main at DFW aren't worth it
Air France / Delta lounges have been awfully busy everywhere I've been so I'm no longer doing those
Cathay in HK is ok-ish
LHR (BA) or AMS (KLM) are insane - don't do it
Ultimately, the AA lounge at DEN is good, the tiny one at SNA too. The big skyteam lounge at MAD terminal 1 has a terrace which is awesome when its not scorching out.
It really depends on the airport and airline.
Ultimately, the AA lounge at DEN is good, the tiny one at SNA too. The big skyteam lounge at MAD terminal 1 has a terrace which is awesome when its not scorching out.