We did it last vacation and it didn't really work for us.
We went at 2:00 on an EMH morning at M.K. By the time we got there we were hot, tired and ready for something really cold to drink, and "real" food. They were nice and brought us ice water when we asked, but they obviously weren't expecting to have to refill our glasses over and over when that was what we wanted at that point.
If I was having a "non-park" day I can see how this would be a fun choice, but after a morning in the park it wasn't the best choice.
You can make ADR's for this, but it's not on the dining plan.