I personally would not get there any more than 10 minutes in advance. It might take a little while before they get you in there but otherwise you could be standing outside for a while if you get there too early. We ate there last summer when it was very busy and we were seated fairly promptly for a 5:30 reservation. We were also seated close to the door where the princesses came out so they all came to our table one after the other so it was good. Personally we did not care for the food that much and if this place did not have the princesses, I doubt it would be that popular.