We went on the 7 day RT cruise from Miami. Never cruised with MSC before and actually had pretty low expectations from the reviews, but thought we would go with an open mind because we really wanted to see Cuba and it was a good price plus we got the Easy drink package and WiFi for free. They will match your status with other lines, so be sure to do that before you go.
We flew into Fort Lauderdale and used the ships transfer to Miami. FLL is a Southwest hub and the prices were better than Miami. We had to wait at the airport for a while before they had a full bus to take to Miami. Next time, I would probably just taken a taxi or Uber.
One thing I want to note here is that the porters at the Port of Miami are extremely pushy regarding tips. Our bus driver told us the porters would pick up the luggage after it was unloaded and we didn't have to do anything. The porters made us bring it to them and put it on the cart for them and then held their hands out for a tip to "make sure it got to the cabin safely". This sounded like extortion to me and it does not make the cruise lines look very good (even though the porters are Port Authority employees). Our dinner mates were from London and they were appalled by how the porters acted.
We had ocean view cabin 9271 (Fantastica), it seemed similar to OV on Royal Caribbean's smaller ships. The bed was only a double, I would have liked to had a king, but it was fine, and we knew this before we boarded. The bathroom was small, but again, similar to other small ships we've been on. The air conditioning in this room did not work very well, I had to contact customer service multiple times to get it fixed, but it did get fixed, and they sent us a bottle of wine and strawberries to apologize, which was a nice touch. Our room steward was very efficient and was friendly. A plus was that we were near the rear of the ship and there was a deck with seating close to our stateroom. As far as the Fantastica experience, I probably wouldn't get it again, the only thing that it included was the room service fee. Many items on the room service menu (like pizza) cost extra, so we didn't bother using it.