My daughter did this last year when we went as a part of her birthday gift. She really enjoyed it and I would say it was worth it. They did her fingers and toes as well as her hair and makeup. The hair took the longest and it was adorable! We did it the same night we planned to go to the Starlit Hui and she looked great. Unfortunately I am unable to post pictures. She still has the dress and I'm thinking it will be in the suitcase when we return to Aulani in a couple of weeks!
Oh, I don't remember how long we were in there, but it was definitely longer than it says on the website!