Overall I guess I would have to agree with you BUT.
Things have changed quite a bit on the shorter (7 day) cruises on the S class. From my very first experience on the Solstice shortly after it hit the water I thought that X had kinda made this class of ship for those on RCL that were looking for something a bit different. This rather than stick with the old tried and true laid back experiences of their first ships. The martini bar action sounds like what you might like.
Not that I haven't had some rockin' times on all my X cruises. But RCL crowd is a little better at having fun..so to speak.
So depending on the length of your cruise and the itinerary I don't think you will notice that much difference if you go on an S class, although all across the fleet there is more of an RCL feel these days.
M class very comfortable also. The Century in warm waters would be fine also.
The RCL ships on their longer trips still tend to be quieter also which I'm sure with your history you have noticed. ....and those S class ships sure are something.
Just remember on S class only two elevator banks and Aft or FWD you need to take a lunch sometimes. :whistle: