Get the latest lunch you can get at Crystal Palace and they bring out dinner food around 3PM. That way you can eat lunch and dinner, too, for the price of lunch. It kind of clears out about that time, too.
HAve been to Cm for dinner and the kids loved it. We went for one of the first seatings and there were not too many people there and the kids interacted with the characters alot. The food was fine for a buffet. Went to CP for a late lunch a couple of times and the kids love the characters also. You can not go wrong in either place. Remember it is all about the kids.