My husband and I did this exact cruise in 2011 and absolutely LOVED the Celebrity experience! Since then, we've done a Celebrity Med cruise, an NCL and a Carnival cruise.
We took our daughter on the NCL cruise, and I also took her on this latest Celebrity cruise. I talked it up, stating that she would definitely see the difference between the NCL cruise and a Celebrity cruise.
Not so much. Gone are a lot of the "modern luxury" things that made you feel like Celebrity was a step above the other cruise lines. Now, it is pretty much indistinguishable from NCL, Carnival, or any other cruise line.