We took our four kids in December. We had dinner at Alfredo's (which they all loved) and then went to the CP. Our four kids are 14, 10, 7, and 2 and they all did fine.
We were able to do this on the dining plan, one credit each, and it was wonderful. The baby fell asleep in my lap, but really enjoyed the music up until then. The older three ranged from really enjoying it (7 year old girl) thinking it was OK (14 year old boy) to being bored (10 year old boy).
They are all used to church also, so it wasn't a stretch for them to sit still. I think it really depends on the child. I didn't hesitate to take the two year old because she LOVES music of any kind, and I was kind of dissappointed when she fell asleep because I think she would have enjoyed it.
One thing I was glad I did was schedule this at the end of our vacation, we had already done
MVMCP and just about all we wanted to in the parks, so it wasn't like it was our first night there and I was keeping them out of the MK, that probably would not have gone over well. I guess what I am saying in a round about way is that there is really no right or wrong answer, it depends on your children.
Have fun!