We haven't done a cruise, but have done the dessert party. If I had to pick again I would pick a cruise instead. We wasn't overly impressed with the dessert party for the cost. While it was nice to do once, I can't imagine doing it again.
I did the pirates and pals fireworks cruise last October and thought it was great! There were lots of desserts / snacks before the cruise. But I think we loved it because of the pirate guests.... if you have pirate fans in your group - I would totally recommend it!
I just did the cruise last week with my 9yo DNiece and really enjoyed it. The had cake, ice team treats, cotton candy, pretzels, bags of popcorn, candy gold coins and beverages.
I just changed our reservations from the wishes party to the cruise. I don't think my crowd would eat that many desserts so late at night and it was $24 more per person for what sounds like an awesome experience.