I've been very happy with it. I fly out of MCI and generally can't use the one Club available (DL) there unless I'm flying DL because of MCI's weird setup. I agree with the earlier poster that it's less useful in airports where you have to pass through another secured area to get to your plane, such as EWR or MCI. Much better in places like ORD and ATL, where your flight and the club are more likely to be in in the same secured area.

They have some weird omissions- last I checked, no Clubs in CVG or CLT. Overall I probably pay more than I would with a single airline club membership because of the guest fees for my husband when we travel together, but to me it's worth it because of the huge variety of clubs we've been able to visit. The ones I can think of include Prague, Zurich, London and Edinburgh; in January we'll use one of the clubs in Athens. No single airline's club would be likely to provide access to all of those places.