We have not cruised with MSC before, only RCCL, but as Grandiosa was the only ship that matched our preferred itinerary at the time period we could have a vacation, this had to be it. We will not cruise MSC again.
It is a beautiful ship, it's sparkling, there's mirrors everywhere, and it's very obvious they are trying to be elegant and luxurious. However, that is just on the surface.
Food: Average food. The buffet seemed great to begin with, but it was the same every breakfast, lunch and dinner. The only things that changed was the desserts, and some days they would have one extra dish. Lunch in the Purple Crab was ok. Avoid the salads, they are drowned in balsamico and vinegar. Dinner at the main dining room was ok, but not the best. And you have to pay for water in the main dining room! Seriously! Pay for water when having dinner! That's just absurd, and I have never experienced this any other places unless one orders a bottle of special water or whatever. That's just MSC being cheap.
Service: Average. Some waiters were very good at their job, but the others were just doing their job and obviously not particularly happy about it. No smiles, no service minded talking to guests, just "what do you want?" when taking orders etc. Waiters working in the buffet were mostly just walking around waiting for people to place drink orders, and not much else.
Cabins: They are great, spacious and well cleaned. With RCCL we are used to cabin stewards introducing themselves to the guests staying in the cabins they are responsible for, and say hello when we pass them in the hallways. No such thing at Grandiosa, we didn't know who our cabin steward was, and most of them didn't say hello in the hallway.
Shows: Some shows were great, specially the Wonderworld and the Michael Bublé-tribute show, but the rest was really meh. The music was also too loud, especially on the show "Rock it". Some of the shows were really awkward as well, with strange costumes (dancers wearing lion heads while just walking around the stage) and very over-sexualised costumes and dance moves. Not that I care so much about this really, but it just seemed out of place and not in tune with the music or songs they were dancing to, and added an awkward feeling to it all. Some dancers you could see were very talented, the two from Colombia (I think), they had some really great performances with latino dances, but their talent were wasted as they mostly had to walk across the stage wearing awkward costumes. And also, try not to freak out over the overly fake smiles that the dancers had to keep on the entire show.
Other entertainment: Bad! Oh, so very, very bad! Some "game shows" in the Grandiosa lounge with entertainment crew from hell and on steroids. A lot of howling, screaming and some confusion about who were going here and there and...well, not very entertaining. And some dance classes. The themed parties (white night, romance, carnival, flower power) were mostly entertainment crew wearing costumes and had to dance with guests. Also it was not much entertainment going on, so it got a bit boring as it was also too cold to sit outside most of the time.
Bars: We did't have a drink package as we don't drink that much soda or alcohol, but we had a couple of beers in the Masters of the Sea pub one night, which was a nice place, but they didn't know a lot about beer or how to tap a beer. When you order a beer, you don't really want half of it be foam. Luckily they didn't object when we pointed it out and we got a new one. The bars were also mostly crowded, I guess because it's not much else to do on the ship except for drinking.
Sportplex was nice, some fun things to do, but very overpriced.
Spa area and gym was really great. Pools were nice, but very small.
Ports were great, the only place we decided on using MSCs shuttle was Marseille. Embarkation and disembarkation went smoothly.
Information flow: Since there are a lot of different nationalities on board they give every information in English, Italian, Spanish, German, French and possibly other languages as well, which take up so much time! But we encountered a lot of people not speaking English, so I guess they had to do it this way. But it was annoying. Some of the crew didn't speak English very good, so sometimes it was difficult to get what you wanted.
Sell, sell, sell! They have people all over the ship trying to sell you things constantly. Drink packages, photo packages, dining packages, spa packages etc. Sometimes they walked around the buffet trying to sell. I understand this is how MSC makes money, but it's really unnecessary to have to avoid ten salespeople when walking from one part of the ship to another. The photographers/people at the photo stands were the worst. They were almost grabbing you and shoving you in front of the camera, and didn't take no for an answer. Lucky for me I am not so easily harassed into something.
Overall: Nice ship, not a lot to do, average food, average to bad service. I think there was only about 2000 guests on board when we sailed, so a lot of room and it felt spacious, but when they have full occupancy I imagine it being quite crowded. As I said, we will not be sailing MSC again.