First time on a cruise, but went with friends who have done a few Viking cruises.
Ship excellent: state room was superb, decor and furniture is stylish, staff outstanding.
One major issue was that our choice of state room (odd numbered cabin) meant that when we docked we were either looking at a wall or at the windows of another boat. We almost never had a view of the river when we docked. Tip: on the Basel to Amsterdam run, choose an even numbered cabin.
Superb cabin looked after magnificently.