We recently took the Scenic cruise from Amsterdam to Zurich and were very disappointed.
Firstly, do not expect to spend any time in either city. You would need to tack on extra days at additional cost. You may end up in Switzerland, but you do not see any of the sites there.
Scenic advertises as 5 star luxury river cruising. Sitting on your sun lounger balcony staring into another boat and someone else’s room, is also not my idea of luxurious. This happened at a number of stops where we were double or triple docked with other cruise lines.