I've had Full Board Premium on my last visit (Stayed at the DLH too), and it's certainly convenient, no money at all to worry about. Everything is covered à la carte (with the exception of the California Grill where you'll be offered a limited Set Menu). You can do Buffalo Bill's Show too one night, which in my opinion is certainly worth it. The food is relatively simple Western Fare (rather filling though), it's the show that's the main attraction, and it is rather spectacular.

Though in order to get anything approaching value out of the cost you would need to do about 2 Table-Service meals per day.
As I travelled by myself this was perfectly fine, but I don't think many children would appreciate an hour long (minimum) break in the middle of the day for lunch.
However, doing lunch at Auberge de Cendrillon with the princesses should placate them most of the time.
