I spent my birthday week on board Reflection. It's a gorgeous ship, and some aspects of the cruise were very good, but I don't think I'll sail Celebrity again. I prefer Royal Carribean and Princess.
The best thing on board was the entertainment. Production shows were comparable to West End and Broadway standards. The singers that played in lounges and bars were all truly excellent.
Our balcony cabin was spacious with a very nice bathroom. Only gripe was that there was not enough storage space for my liking.