We have traveled quite a bit but this was our first Riverboat Cruise! It was a wonderful experience and a great way to some of European cities we hear so much about plus some smaller towns that you don't hear so much about. The service, the food, to cabin, and the excursions were all well thought out and executed. We had lovely weather which allowed us to enjoy the upper deck a lot! So nice to be floating along just enjoying the scenery for awhile and then exploring a town without having to pack and unpack or figure out where to eat that day! The locks were interesting to experience and see and the captain and his crew have our utmost respect. We would highly recommend Viking!
My only suggestion is to offer bike riding along the Danube as an excursion. We saw folks gathering for a ride while walking to the bus for one of our excursions.
Our cabin was small but very efficient. We did not have a balcony which made the room smaller though and next time we will make sure we have that little bit of extra room that can make a difference. I was thrilled with the American Outlets for curling iron, etc.