I have never cruised before, so all my star comparisons are with ground.
Public spaces--Functionally they were excellent except pool area was small and extremely crowded on sea days. Decor was modern--Nice finishes and fixtures, but art and "whimsy" often pretty dumb. Main dining room looked like a high school prom with a Jetson's theme, but you got used to it. Overall feeling was closer to a convention hotel than the Broadmoor.
Rooms--Small but okay for 2 because of balcony. Had to run extension cord across room to get plug in by bed. Good bed. Slept very well.
Service--Great. Only weakness was pool area understaffed.
Food--Excellent. Main dining room offered a big variety of 3 and 4 star dishes. Buffet had good selection of more basic items for breakfast, lunch and snacks. Room service breakfast was really convenient.
Entertainment---varied in quality from 2 to 4 star. Heavy on music. Lots of nice small music acts performing at various times throughout ship.
Shore excursions--did private except for Naples. Had unused credit so took Pompeii On Your Own. Very nice bus. Guide didn't provide much information in bus or handouts. This caused a problem because Pompeii signage is really bad and they don't give you a map. Had to wait 30 minutes in line to get tickets, but amount of time at sight was extended, so somewhat rushed through site. Experience with private tours much better. Particularly recommend Ephesus Shuttle and Sicilylife.
Overall--very nice way to see lots of sights. Much more convenient than changing hotels all the time. More restful travel than train or plane, plus some really pretty views from ship. Would do again if I liked itinerary.