Having just returned last week from the Millennium, 13 nights-Mediterranean and having cruised on six different cruise lines (Premier, Norwegian, Carnival, Royal Caribbean, Princess and Celebrity), I can add a little...
Overall, I place Celebrity at the head of the class...
The food and service is excellent, the ships (at oleast the Millennium and its sisters) are incredibly well laid out...Very rarely were we even aware that there were 2300 passengers on board--Dining room seating was nowhere near as cramped as on, say, Carnival Elation (a ship I actually like quite a bit)...There was never any crowd at the shows which the showroom couldn't amply handle...Elevators were only a bit difficult at midship when folks were returning from tender ports and a tender would arrive...Lots of virtually private areas to hang out on the ship, even on "at sea" days...
The ship provided some programs we haven't seen much on other lines...like "enrichment lectures"...They actually had 4 guest speakers on board including the very popular Ike Pappas, veteran CBS newsman famed for his coverage of the JFK Assassination...
The overall atmosphere was very refined, dignified...Everything was handled with a touch of class not seen on other lines...
Even though traditional with dining room seating, there were loads of additional choices...including Casual Dining sit down restaurant, the Olympic Dining Room--extremely elegant restaurant duplicated from the Titanic and a nightly Sushi Bar from 6-10 each night that was absolutely excellent...Also, Ice Cream available daily (I'm not sure of the hours, but it seemed to be there whenever I wanted it)...
The ships have an outstanding ratio of balconies and suites...
The itineraries are excellent...Ours started and ended in different ports allowing for less backtracking and more ports in between...
Yes, very few blaring announcements...