We weren't sure what to expect when booking our MSC 11-night cruise because the reviews on here had lots of conflicting information. All-in-all the cruise was great. Staff was amazing, very hard working, friendly, and personable. Got to know everyone quite well in the 11 days and was sad to see the cruise end.
The ship is designed with a lot of back-and-forth walking from venue to venue, and with such a large number of guests it was difficult in the evening between dinner seatings and shows to find seats in the lounges or even find your way down the main hallways. Couple that with 24/7 entertainers and some of the lounges got quite full. (Looking at you, Sasha and your shenanigans in the golden lounge!!) Once you're settled in a lounge the parties can easily stretch from 8pm-2am every night. The band in the Black-and-White had everyone up dancing all night.
Days at sea were busy. Tons of entertainment, tons of pool parties, but the deck chairs were always 100% taken, and lots of abandoned towel 'reserved' chairs with nobody using them. We ended up just laying on the wooden deck near the garden pool most days, without a chair. Pool attendants didn't really adhere to their 30 minutes and it's free rule. If you're looking for quiet, book the Aurea type experience. Aurea come with private sun-deck included, which would have been quiet and reserved for few people (or the Yacht Club for serious bling-bling). Otherwise it's party non-stop.
The stateroom was good enough. Tons of storage, very clean, a/c worked great. It was dark and small, but what do you expect with an interior stateroom?
*IF* you plan on heading off the ship at all, book an excursion. I'm sure the island is very nice, but you need to get thru the port first, which can seem like a never-ending gauntlet.
Take a taxi to Banana Beach. You won't be disappointed.
Eagle Beach is amazing and close to port.