Cruised on the MSC Seaside and it was the worst cruise I've been on (and I've travelled on Disney, Costa, Carnival, Princess, Royal Caribbean, Norwegian and Holland America). The seaside is a nice ship and the pool on the back of the ship was very nice, but that where it ends.
Worst food ever tasted on a cruise. Nobody eats all their plate in the dinning room because food is too bad... but the alternative of the buffet is so poor that you have nowhere else to go. The pastas are horrible (plain watery sauce red or white...). The buffet has always the same menu (except a few exceptions). Everything is way overcooked.
Shows are bad. dancers are good but the shows are so eclectic and the costume and choreographies are very basic which makes a 40 min show difficult to watch completely.
Room bigger than usual (beside a handicapped room), equivalent to 1,5x the size of a normal room with the same furniture and bathroom than a normal cabin.