We were very concerned after reading some of the reviews on Carnival Imagination on this board. While the ship may be somewhat older, the amenities on the ship are very good.
We stayed in a hotel near FLL the night before and took a ride to the port of Miami. We also flew back on an 11:45am flight from FLL, so we disembarked with the "early disembarkers" at 0830am and that worked out well.
My daughter has many food allergies: she is severely allergic to eggs, wheat, milk and gluten. So a varied, nutritious and tasteful diet for her can be a challenge.
Our cabin was close to stairs but not very noisy. We switched on the a/c at night to generate some white noise, and slept peacefully.