This was our second cruise with MSC. The Opera is one of the smaller ships they have. The public rooms are not very spectacular. The cruise was very pleasant however and very easy an well organised.
The cabins are quite small (only the bed and a chair with small board, no couch), but cosy. All the ship was very clean.
MSC Opera has about 700 cabins and 1800 people sailed on board. So buffets tend to be very crowded. The buffet restaurant is on one of the top decks. The outdoor space of it is not at the aft but in the middle, wich makes it a bit noisy and there is practically no view but only to the sky above.