Millennium is a spacious and hospitable ship that features an eleven deck high atrium and a conservatory . It offers a fine cruise experience in a good selection of tastefully decorated public rooms.  Celebrity Millennium passengers tend to be 40+ and Mostly American. When all cabins have double occupancy, the ship provides a space ratio of 46.7 tons per passenger and a crew to passenger ratio of one for every 2 passengers. At full capacity the space ratio is 37.2 tons per passenger and the crew ratio is one to 2.4 passengers.