This was our first cruise and we chose Celebrity because of the Jet Set Sail package.
Good points: the ship is well maintained and despite the number of guests on board, it never felt overcrowded. There is plenty of choice for food and drink, and the quality is generally good.
Negative points: The shore excursions are vastly over priced with a little bit of planning, you can do just as well yourself. Service is mixed. Some of the staff are happy, smiley and courteous, whilst others, especially some of the wine waiters and bar staff could be surly. I felt that some nationalties, most likely those that tip well, were given priority. I could see little advantage from booking Concierge class. We did not feel that we were treated specially in any way and things like the free afternoon hors d'ouevres are frankly a waste of effort. ( We asked for something sweet instead, but were refused).