Peggy, I totally agree with you about the lowest common denominator. And,formal attire has never added weight to our luggage.
So, if I understand this correctly, there will be a night or two on longer cruises designated "Formal optional" where people will be dining and socializing together, some dressed casually while others are in formal wear? That seems bizarre to me.
As far as dress code goes, from what I've observed from Vancouver to "almost" Shanghai, Regent doesn't enforce the dress code anyway. I've seen jeans in the dining areas any number of times. Sorry, for saying this (and I admit it's after a glass or two of wine) many people on this cruise interpret "elegant casual" to mean that they can dress any way they choose, dress code be damned. Many look like slobs. With the change in dress code, I'm sure this will continue or even degenerate even further.
It seems to me that if World Cruisers and other long cruises have their own dress code that this will lead to more of a "class system" on Regent. I'll be sorry to see this happen. Not exactly my idea of luxury.