I took my then 4 yo DD and 12 month old who has food allergies.
My 4 yo absolutely LOVED it. Still talks about it. Of course, she's princess obsessed, but getting to eat ice cream, mickey bars, cotton candy, etc was a really fun afternoon for her (we skipped lunch btw). We watched the parade from a better vantage point at another time during the trip (and have seen it many times) so the only downside is the far-away viewing and that didn't bother me. The character interaction with Tiana and Naveen were priceless, especially after the parade when they came on the boat. It wasn't crowded, and the kids all had a LOT of fun - dancing, playing music, etc.
I mention the allergies because I felt their allergy options were very limited. They had no options for the cupcakes/other treats, and their ice cream sub was a sorbet. Had my 4 yo had the food allergies and I paid for her, I would have been very disappointed in her options.