We're just back from one of these Scenic cruises ( Danube / Rhine) and this video describes  perfectly what it is like.

I too enjoyed a Scenic river cruise on this same ship a few years ago.  It was the Christmas Markets Amsterdam to Budapest cruise. An ongoing highlight were the Christmas Markets at every stop the ship made.  Mostly multiple Christmas Markets at each stop which really set a fun tone for the season and cruise.  The Cruise Director Yvonne De Sera was beyond exceptional and nothing was too much trouble for her.  She was a dynamo for the full two weeks straight.  The food and beverages were of the highest quality and there were excellent choices for the daily external activities and onboard activities from special invited artists/performers.  One afternoon a glassblower got on board and gave a demonstration of his art accompanied by a readily accessible fire extinguisher!!  Scenic is an Australian owned brand and so the majority of guests are Australian with a sprinkling of New Zealanders and Canadians.  There were 3 or 4 American guest couples as well.  Highly recommended.

Beautiful!

My only concern is clothing.  Since we are adding another two weeks I worry about bringing men's suits.  I hope one dinner jacket and no tie is okay?