The ship is very big, so be ready to walk, however, it's incredible, with delicious foods for all tastes, comfortable cabins, an excellent service, with some entertainment (but not always), activities such as videogames, F1 simulator, football ("soccer", for some), baskteball fields etc. The ports in Brazil are very direct to your ship, but I can't give a review on shore excursions by MSC because we visited the cities on our own.
By the way, if you're a fan of disco, there's something for you there, but I wouldn't say it's really that great if you're a hard partying person.
We embarked in Santos, and the trip followed as we visited Búzios, Salvador, Ilhéus and Ilha Grande, until we return to Santos.
Nice cabin overall. Smooth bed, warm blankets, very decent bathroom/toilet and shower. I only had a tiny problem with a failing light bulb that was quickly fixed in the blink of an eye.
Simple and practical.