Recently returned from an 11 night cruise around the Caribbean with MSC Opera. Although I'm not an experienced cruiser (only my second time) I was very impressed by the whole experience. Initially I was worried about the long haul to get there (ie. early morning flight from Heathrow meant an overnight stay at the airport, 9 1/2 hours flying time to Miami, plus another hours transfer to Fort Lauderdale... and all the time worrying if the flight was delayed or cancelled... would the ship really wait for us at the other end as the MSC agent said it would!!
In fact the flight with BA WAS late leaving Heathrow but we made it to the boat shortly before it sailed... so i never got to test the theory. Anyway once aboard apart from a few initial hiccups, i would say that it was a very enjoyable experience. I travelled with my daughter of 8 years and was hoping that the ship was as family friendly as i had been led to belive. It was, she had a great time and I have much praise for the Italian entertainment team who made a special fuss of her.
All in all I would say it is quite brave of MSC to try to break into the North American cruising market. Their style of hospitality is very Italian and at times not all that suited to the demands of the predominantly older American travelers. I met many Americans onboard who were having a great time but i met just as many who really never stopped complaining and comparing the ship (badly) with all the other cruises they had taken. Pity really because objectively I don't think there was that much to complain about. Perhaps the cabins are a bit smaller than Carnivals/Celebritys (whatever!) and perhaps the food isn't available ALL day long and god forbid is ITALIAN but i think the Italianate style of the whole cruise was a plus not a minus. About 30% on board are Europeans (not many Brits like myself) but quite a few Italians, Germans and French and the rest all Americans or Canadians. This makes for an interesting crossover of cultures which was no doubt challenging for MSC but all in all handled very well.