You might want to check out the Dining Plan board to do more research on this...there are many people who kept very careful records of what they ordered and how much they saved, etc.
I personally think it is a great deal. Unfortunately, my dd will be an "adult" next trip, and she doesn't eat anything except kids menu stuff, and I can't bring myself to pay $38 a day for kids meals. Well, we've got a year, amybe she'll aquire more mature tastes