Keeping things simple, there are only four cabin categories: insides, outsides, balconies and mini-suites. The inside cabins, outsides and those with verandahs are all the same size -- in a word, small (at 140 square ft.). The clever use of mirrors and ingeniously designed storage areas mitigate the petite size of the accommodations, as do the cheerful spreads, bedskirts, pillows and bolsters used in the rooms.
I was in a standard balcony room that had a small but cozy feeling, especially with the real lamps at the bedside and the fact that the table on the balcony was really a table.
The shower-only bathrooms are small but quite functional, with great water pressure and plenty of hot water. Shampoo, shower gel, soap, a sewing kit and a shower cap are included amenities.
The mini-suites are larger tt 270 square ft. (including the balcony) and feature a seating area, entry foyer and a bathroom with a tub. But book ahead for these -- there are just 28 mini-suites on MSC Opera.
All staterooms have mini-fridges (stocked; check the prices before you munch), remote-control satellite television, nice closet areas with plenty of hangers (mini-suites have walk-in closets) and several drawers.
One important note: The standard balcony cabins, located on Decks 9 and 10, aren't necessarily kid-friendly because the verandahs are enclosed only by widely spaced metal bars. Make sure you ask the staff for a custom-made netting which can be stretched across.
Ship-of-Shame Note: There are only four handicap-accessible rooms and they are all insides. The ship otherwise has made few concessions to the physically challenged.