Well... I went last year for one night. It was going on twice during our stay. I wish I would have done the second night. Mostly because for about an hour of it we were having dinner at BOG (only res I could get). I only got to meet Jack and Sally which was my number one priority and my sister and niece got to meet the 7 dwarfs.
It was very crowded but it was the week of Halloween too..so that may have played a part in it.