I do see your point, Paul, & in that regard, those features do set some ships apart from others. But to me, at least, "premium" is evidenced through attentive service & ship decor which create a certain atmosphere on board, & I think the M class still provide that.
I get a chuckle when I hear the M class referred to as old. In ship terms, they haven't even reached middle age! .......Now, I'm getting old!