We did lunch and like Colonel, I would recommend trying it once, but it's definitely not going to be a must-do for us every trip. THe line to get in was the longest line we waited in for our entire trip--50 minutes. We did arrive 30 minutes before opening and the CM's actually stopped the line about 3 families behind us. We were almost at the end of the bridge at New Fantasyland. I would definitely try to fast pass this. The photo below is our vantage point from the back of the line.
The lunch and dinner menus are different, but the dinner menu didn't honestly sound that appealing to me, so we just did lunch so we could see the restaurant. I remember thinking that the sandwiches were tasty, but they weren't really memorable. We tried the strawberry lemon cupcake and it was very nicely presented, but I didn't care for the icing. (It's probably really good, but I must have a very mild allergy to something because certain icings stick in the back of my throat and my throat feels like it could close up if if I eat a bunch of it.) The cake itself was good.
We could sit anywhere and we chose the ballroom which was the largest and (I think) the nicest of the three rooms. We were free to move around and take photos, but it was tricky to dodge the waiters and all of the other people who were doing the same thing, but it was nice to have the opportunity. THe lighting is a little bit on the "red" side, so photos are a little off.
It was nice to experience and I would do it again, but it's not fabulous enough that we will allocate time here on our next two quick 5-day extended family trips.