Personally, I think the Admiral's Club is well worth the money. Yes, the food stinks, Yes, there are too few computer workstations with Internet access, Yes, they could offer a better assortment of free beverages... But with all of that said, I still think that if you fly once a month or more on AA, then you are spending a decent amount of time in airports (esp. now that you can't show up at the airport 20 minutes before your flight is supposed to leave). For those who fly mainly international, like myself, some of the "value" less clear, since yor PLT card gets you into any OW lounge when travelling internationally.
However, checking in at the AC saves time (generally), and the agents are in general much nicer than at the traditional check in counter IMHO.