Viking Delling was a very organized machine. The whole cruise experience: shore excursions, dining, room service, drinking, check-in & out, waiters; ran like a watch. The crew’s English language skills were excellent for a mostly Slovenian crew.
There are a few areas for improvement. The biggest shortcoming on the cruise is the lack of use of the top deck, which has the best views and the only exercise track. On the Main-Danube canal and if the Danube is running high (Spring and early Summer), the deck structure is collapsed and the pilot house lowered to clear bridges. Nobody is allowed on the top deck, and the only outside space is a small space forward with glass walls---not many photo ops except through windows. The Downton Abbey film shows the boat in Budapest with the deck awnings up, which wasn’t the case on our cruise.
The Viking river cruises cater to a more senior clientele. Later in the cruise the director divided the shore excursions into walkers and non-walkers and this helped. The main problem is a shortage of shore time accentuated by slow moving groups. In Melk and Nuremberg we stuck with the tours, which were back at the boat for lunch. In Regensberg, Passua, and Vienna we did not take the bus back, but struck out on our own and had a better time. In Melk the town and abbey require more time than was available.