We got a free upgrade to concierge when we checked into Yacht Club in August. We enjoyed it, but I wouldn't have paid for it. The best part for us, lounge-wise, was the 6:30 a.m. coffee and the breakfast food. We didn't make meals out of the midday or evening snacks, though we did grab some munchies and sodas a couple of times.
I had never had turn down service in a hotel before, and I liked that a lot. It wasn't so much the covers on the bed being turned down, as much as the bathroom getting tidied up, fresh towels delivered, and the way the housekeepers arranged the kids' stuffed animals. Turn down service is available free of charge at any of the deluxes, though, so this isn't a reason to pay for concierge.
At the time we were there, concierge would have cost an additional $140/night if we'd paid for it. We liked it, but we wouldn't pay that kind of money for it.