We have sailed many ocean cruises, but this was our first river cruise. We liked the idea of being able to see multiple cities in Central Europe while unpacking only once. Overall, the cruise was OK - not sure it is a great value for the price paid, but it did deliver us to some great destinations.
Booking - Difficult. Viking likes to have you "call for a quote" rather than just telling you what the price will be. From the moment we booked we tried to find out what time the ship would be in the cities (sometimes the ship moves after your tour leaves). This was a difficult exercise with limited success - we NEVER found out what the actual schedule was going to be until we were on the ship. It made it very difficult for us to make plans for our free time. It felt like they wanted to just control everything for us and did not want us wandering off on our own having fun without them!
Embarkation in Budapest was great. We had made our own flight arrangements and took a taxi from the airport to the ship. It was very early afternoon and our stateroom was not ready yet. We had a nice light buffet lunch on the outdoor terrace and planned to head out and explore the city. We were pleasantly surprised to find our stateroom was ready, so we moved in and then headed off to explore.
Small - just room for the bed, no chairs. Bathroom small, but efficient. Window is useless - small, high up and mainly not useful as it was up against another ship, or the dock, or it was under the gangplank. It was noisy when the ship moved - gurgling noises, thruster noises, banging as we entered locks...