We went to the
MNSSHP on Sept 14th. It poured and poured and poured some more, so I'm not sure if it would be the same. The dance party that we saw was in Ariel's Grotto and it was packed while it was raining. (We actually found it because I did not realize that a dance party was there and we were looking for a place to dry off for a minute.) It had a dj, who was very entertaining and Suzy and Pearla from Cinderella danced with the kids. They did everything from the Hokey Pokey to the Time Warp. It was very kid oriented, but there were plenty of adults shaking it, too!
I will admit that I was hesitant about buying extra tickets after we had spent so much on tickets already. Even though it poured and messed up the timing on Hallowishes and the parade (we still don't know if they had it or not) WE HAD A BLAST! I would do MNSSHP again in a heartbeat!
Hope that helps!