We went opening weekend last year. It was crowded, but I'm sure if you compared it to Christmas, or the summer months, not bad. While it was HOT, the afternoon was not as crowded as the evening.
Allears (I can't post links) has last years information explaining what was available.
I say go for it! If the kids are young, let them do the masks. Try samples of all the food. Watch the shows and go to the Eat to the Beat concert. If it too much for hubby and kids, leave!