We boarded MSC's Poesia with an open mind. I have read many poor reviews, but we paid a very reasonable price for an 11 night Christmas family cruise, and you shouldn't expect to get champagne if you pay only for sparking wine!
The ship is quite superb! It is among the best I have ever sailed on, public rooms were attractive and in very good taste, and kept immaculate. Cabins were kept beautifully clean, and are spacious and more than adequate. We encountered very heavy seas on more than one occasion, and this large vessel coped well with the conditions. We were on a winter cruise, but did note that the lack of open deck space might be an issue in a warmer climate where more time would be spent outdoors.
The food onboard was very hit and miss. As other reviews suggest, if your taste is conservative (steaks, lobsters, roasts) then go elsewhere, but if you are prepared to try the Italian flavors, the risottos, pastas, soups and salads were generally quite good. I would say, however, that whilst we always managed to find something fit to eat, none of the meals would really rate as much more than adequate. Getting really hot food seemed virtually impossible, with the exception of breakfasts in the main dining room.