We're experienced cruisers on the higher end (Crystal, Seabourn, SilverSeas) lines, this was our first trip on a mega-ship. It was the middle leg of a three ship trip including Crystal Symphony New York to Reykjavik, this ship Reykjavik to Southampton, and Cunard Queen Mary 2 Southampton back to New York. We knew it would be unfair to go directly from Crystal Symphony to this ship, and we prepped ourselves by having no expectations here, but we couldn't help but compare.
Starting out with no expectations, we were not disappointed. Everything was generally adequate. Dining room had good food, but not great. Windjammer buffet food was barely adequate, often the wrong temperature and sometimes stale. Some of the entertainment was good, none was great. The movie "theater" is horrendous. Ice show was good, but not worth what must be a huge overhead for the ship. The ship itself is beautiful, but crowded. Front desk helpful and friendly, but always a line. Cabin steward and most waiters were very good and friendly. HATE being nickel and dimed all the time.
Bottom line: We'll take her again if the only alternative to getting there is a long airplane flight.