The cruise on the Elbe was our first river cruise and first experience with Viking. The biggest problem we had was that somehow, even though I had emailed our flight arrangements to two Viking employees at their request and paid the rather expensive transfer fees (more than the hotels charged), we were not on the list to be picked up at the airport. The Viking employee who had arrived to pick up a later group told us that we would have to provide written documentation that we had paid the fees or that we could take a taxi. She did not handle the situation well at all, and we were angry at the way we were treated and got off to a bad start with Viking.
However, once that was settled, the cruise was wonderful!
The Prague hotel was lovely but not convenient to the city but the shuttle buses worked okay. The one we wanted to take back to the hotel was full, and we barely got seated. Perhaps a more walkable location would work better.
We did not mind the small size and enjoyed looking out our window at the river. The only issue that was a bit difficult was the shower being part of the bathroom floor, so we found it hard to keep the floor dry. Still, no real problems!