To return to the topic of this thread IMHO, considering everything, the Celebrity Mclass ships, with the possible exception of the Constellation, are in no way premium cruise ships. Now, the new ships just introduced by Celebrity, IMHO should be considered premium ships.
Getting back to the subject, I might point out that everyone is entitled to their opinion which Debra always gives however that opinion is not shared by the vast and large majority of cruisers on the M class ships. This has been shown for years by the various polls, readers surveys, etc. Debra may argue over the methodology of the presentations however when almost all given Celebrity's M class ships high marks.
Additionally, just to point out Constellation is in dry dock right now getting the S class treatment and Millenium was in drydock last year for major work.