We've cruised with MC four times - 3 times on Opera and once on Armonia. I have to say that I'm baffled to hear criticisims of the food, which in my opinion is much better on MSC than on Celebrity! MSC food is very italian, which is excellent in my book, and is always served fresh and hot, unlike on Celebrity where it's impossible to get a bowl of soup brought to your table any better than lukewarm.
The dining room on the Opera offered excellent choices of appetiser, soup, pasta and risotto courses in the Italian style, entrees that were freshly cooked (with alternatives always available, or your special requests) and much better desserts than I've experienced on Celebrity.
The entertainment on MSC is not so good, however, largely because they're trying to cater for so many different nationalities and it becomes bland and a tad boring.
The ships are kept scrupulously clean, better than Celebrity or Princess in my experience.
Cabins are not so big as on the other lines I've mentioned, but service is impeccable and, given their pricing, MSC represent excellent value for money.