We chose this for the itinerary viz Venice, Ravenna, Split, Dubrovnik, Zadar. We usually go P and O so were a bit worried about the ship being American. The fact that the clientele was so varied actually was a benefit- we really enjoyed talking to Americans and Canadians. The ship was pretty much the same as P and O though so that was easy.
P and O however are better for various things- the embarkation process was not so smooth; but the major disadvantages were the entertainment (the evening shows were pretty poor and more importantly there was nothing during the day except shopping, no lectures except for a very boring travelogue, no classical concerts etc), the laundry ( no self service laundrette and the laundry we did pay for didn't even get the clothes clean), and the tea (no joking matter for an Englishwoman! to have no tea making facilities in the cabin).
BUT the major advantage was the drinks package- it was so relaxing to not have to fuss about what to drink or how much to get, and all good quality. This alone as well as the itineraries would make us use Celebrity again! The service of course was fantastic, and the meals (but do Americans not like cheese??) I would recommend people to go for timed dining, it is so interesting to get to know different people on your table instead of having to introduce yourselves to new people all the time. NB another plus point for P and O is that lunch in the dining room is available every day.
can't remember the number but it had a balcony, on deck 7. It was great as was the steward. Some people don't bother with a balcony but to us it is essential for the feeling of space and fresh air and views.