This was our second cruise with Celebrity, having previously sailed the Equinox a couple of years ago.
Embarking in Southampton, we noticed a significantly higher number of older passengers than with other cruiselines. Accessibility for disabled passengers (who were numerous), appears to be good, and the staff were highly efficient in providing assistance where required. In terms of the nationalities of those onboard, the majority appeared to be UK, then US, with a smattering of other nationalities.
The ship itself is beautiful and spotlessly maintained - she is very similar to the Equinox, her sister ship, as far as my memory will recall. The itinerary was fabulous - I had long wished to visit Iceland and the some of the Norwegian Fjords.
Our room facilities and attendant were great - in our limited experience (RCCL, Cunard, HAL) we think that Celebrity probably have the best standard staterooms at sea, with plentiful, well-thought-out storage.