For a purported "river cruise" there was way to much riding on buses. Two days were spent getting to the boat and then going to our departure city, Paris. Plus during the cruise there were long bus rides to Heidelberg, Rothenberg, and one other city whose name I forget.
The boat itself was well laid out. Our cabin was more than adequate, with nice touches such as a heated floor in the bath/shower area. The crew also worked very hard to make everyone happy.
Food quality was OK, but nothing special. Because we were in Germany there was a lot of emphasis on "heavy" foods, i. e. sausages.
The local guides were of inconsistent quality. Two were outstanding, one was just awful, and the rest were average. Since we had heard the the guides were special on Viking cruises, this was a disappointment .
If I were to do another Viking cruise I would focus carefully on how much bus riding was involved.
Nicely laid out, more room than we expected.
Heated floor in bathroom was a nice touch. And consistently hot water and good shower pressure were great.