I would say experience it for yourself at least once.
For us it was a fun filled night as we bought special holiday hats and enjoyed a variety of special character encounters in Adventureland, Tomorrowland, and Fantasyland. Posed for our special CP photo which you receive later by mail...but we did miss out on the hot choclate.
Our perspective is you live once and your children are only this age for a short period of time. Enjoy the times and create the memories...if you have the thought of doing it...just do it, you are on vacation