If you want a good cruise, I suggest leave Costa well alone. We hated everything, from embarkation procedure to disembarkation. Couldn't wait to get off. I suggest the management go on cruises with their competitors and learn how to run a cruise line and treat guests. I probably don't have enough space to write all our complaints, but here's some.
Our cabin had an interconnecting door with the next cabin and it may as well have been open, as we could hear next door talking and the guy snoring all night, so we hardly got any sleep. We asked to be moved, but were told the ship was full. It had 1500 people out of space for 1900!
The food was absolutely dreadful, both in the dining room and in the buffet. Full of butter, cream, cheese or all of them. The meat was so overcooked, you could hardly cut it. After breakfast, you could not get a free cup of coffee. My wife is dairy intolerant and the staff from the chef down, couldn't care less.
The Italian staff were generally rude, the other staff, excellent. Eve, the English rep on board was 10/10. She helped any way she could, but was up against "company policy." Which meant, do nothing.
Hygiene on board was terrible. Hardly anyone sanitised their hands and there was no policing of it. People filled water bottles beside signs saying don't do this and staff standing beside them, saying nothing.
Apart from the interconnecting door, which allowed all the noise from the next cabin, it was as expected.