I'm AUS based and fly everyone but have the AA world eite card and use the AC often as there is only 1 small(ish) terminal so it's easy. DL is opening a lounge here soon but like UA they will be restricted to their own airlines/alliances. No priority pass or Centurion lounge. I will definitely drop the card and AC membership at my next renewal. Hopefully another option will magically appear by Nov. I'd pay a fair amount ($1k?) for lounge access in AUS when flying anyone.