This had been so helpful to me that I will try to do for you also.
Background: Myself (mother) and daughters, 21 and 18 went on Spring Break cruise. Here's our thoughts... Don't book from Expedia - go directly to Carnival and the airlines and book your arrangements. This would have saved me about $100.
Now about the cruise. The ship could use a renovation - things looked a little worn. Not enough to complain about, but Carnival needs to do something. We signed up for the late dinner - 8:30 - and was glad we did. It gave us the full day for our activities without the hassle of being rushed. Plus we were able to go directly to the show.