TL;DR - My husband and I enjoyed this cruise very much. We're in our mid 30's and have no kids and we went by ourselves, so I have nothing useful to say about kids or large groups.
DEPARTURE CITY - MIAMI
We didn't stay at a hotel near the port because my husband's parents live in Hollywood so we stayed with them and they drove us to the port. The only hotel I know anything about near the port is the Mondrian, which is pretty nice and was filled with young, beautiful, fashionable people the day that I was there for a wedding.