The Mediterranea was new in 2003. Our cruise in November found it to be a delightful ship. It's very (my wife's term) glitzy. Lots of marble, impressive atrium, very nice public areas and small secluded lounges that make the experience seem intimate. Surprising in a ship so large.
The cabin staff was excellent and the room (ours with a small balcony) very nice. This was our first trip with a balcony and for our style found same to be overrated.
While our waiter and busboy were excellent, the food itself was spotty. One evening my vegetarian entree, vegetables tempura, was almost inedible. The batter had parted company with the vegetables and what remained was badly singed. One night the service was inordinately slow. Our waiter had an adjoining table that was extremely high maintenance throughout the cruise, but that didn't seem to account for the delays that seemed to eminiate from the kitchen itself. Lunch and breakfast were fine. One shortcoming was a lack of informal eaterie, other than pizzia, outside normal meal hours.
The shore excursions were predictable and typical for the Western Carribean. We took the ships excursion to the pyramid at Chi Chichinitizi (sp) and since we arrived early and had an excellent guide found it to be well with the experience. The sole problem was with the buffet lunch that came with the excursion. It was poorly planned and executed. The venue didn't seem prepared for a crowd the size of ours and the pushy nature of our fellow passenger didn't help.
The Costa line attracts a lot of Europeans and we enjoyed the cosmopolitan nature of the cruise. One word of caution. There's more smoking in the public areas than is common in the United States. It takes some getting used to.
Overall, we thought the cruise represented a good value and would certainly consider taking Costa again.