We did this in 05 and my kids LOVED it! Both of my DS's were called on to be in the show. One was Gaston and the other was Papa. As mentioned, Belle stays for a meet and greet after each performance and will gladly pose for pictures and sign autograph books. We will definitely be doing it this time around with my DD3.
I would get there early! Also, by arriving early you might have a chance of grabbing a bench in the shade. We went during the lunchtime and I think it may have been a bit less crowded due to so many people eating at those times.