My wife and I traveled from Hong Kong to Taiwan, Vietnam, and back to Hong Kong On Celebrity Millennium in March 2012. We had done a similar cruise some 5 years ago with Royal Caribbean, which we thoroughly enjoyed, and thought we could repeat the experience.
A couple of previous reviews have commented on the 3.5 hour check-in fiasco, and it was without doubt one of the worst I have ever experienced in my twenty or so cruises so far completed. It did at times get quite ugly, and threatening.
It was our first time on Celebrity, and billed as a step up in standards. Regrettably we did not find it so. The staff were great, always happy and willing to help, and the service in general was excellent. The food in the main restaurant was somewhat mundane, and lacked finesse and imagination.