The Celebrity Century is an older vessel in great condition. The downside of the older vessel, and it is a HUGE downside, is that you can hear PERFECTLY through the walls of the cabins. I have NEVER experienced this before on a cruise ship. We asked other passengers in different types of cabins, and they agreed that they experienced the same problems. I probably will never sail on this particular vessel again because of it.
That said, the service is excellent, the food was excellent. Probably the most attentive dining experience I have experienced on board. Our room steward was excellent. The beds are harder, but asking for added mattress pads did help.
The entertainment was average to poor. One group who performed American music, had such strong accents that it sounded like we were in a foreign country listening to imitations of American music. The Elton John song performer just totally sang off key. The dance productions were very enjoyable.
The passage was relatively smooth sailing. :) We departed from San Diego on a Monday. That evening was smooth. Tuesday it was still cool California coastal weather temperatures, but the winds picked up. By evening the boat was really rocking with 17+ foot seas. Wednesday was smooth again (very light rocking) and remained so for the rest of the cruise. Weather also became warmer, to enjoy laying out by the pool. I would say the first sea day and the last sea day are the only days too cool to enjoy on the open decks.
Loved the fact that they offered daily Zumba classes. One out by the pool and another in a lounge area.
They also offered interesting daily lectures.