Previous experience with MSC Opera were excellent. The combination of ship and destination (Cuba) was the trigger to book for this cruise. What a major disappointment!! The upside were the cabins, but the rest was really a disaster. The staff - with exceptions -was not motivated and sometimes rude. The food was in general average (we - wife and I - are still suffering from a parasite and are on antibiotics) and hygiene questionable.
On the very first day I addressed one of the officers in the main dining room, when I visited the lavatory and one of the waiters came out of the toilet, didn't wash his hands and resumed service. I know that +60% of the people don't wash their hands, but it is unforgivable for waiting staff.
We could not book the vintage car excursion anymore and had to arrange it ourselves. Through Tripadvisor we booked the top ranked company. In hindsight, we were better off. MSC would have charged us €92 p/person for the tour. We (4 people) paid $80 (excl. tip) for the 2,5 hrs tour with a very good guide (Jorge), or $20 p/person. MSC, this is over charging, i.e. 368€ vs $80! The cigar and rum tour was interesting, but you may skip the Havana Club commercial visit. We had similar experiences in Jamaica, Cayman Islands and Cozumel and organized our own shore excursions with Tripadvisor as our reference.
The cabin was OK and clean. We did miss the amenities fellow travelers received, but all in all it was good.