We recently returned from a river cruise on Viking. The ship was fine, wait staff fine, food fine, not exceptional. The cruise was a mess, according to Viking it was due to low water levels on the river. I discussed this with our travel agent and Viking prior to our sail date and we were assured no interruption whatsoever in our itinerary. Wrong. We had to change ships, we had to take a bus for hours to reach destinations since the ship could not sail, we were unable to enjoy our balcony view due to another ship docked right next to us blocking our view (we could touch their ship that is how close they were).

I would not recommend Viking, I have a friend who sailed on another line the same week we did and had no river issues. Smooth sailing all the way for them.