My husband and I went on a Viking cruise in August, 2016 down the Rhine River. We had watched many of the YouTube videos and had great expectations of the vacation, but the actual experience didn't measure up.
We did get to visit quite a few ports, which was very nice, so we got to see quite a bit along the Rhine River. We went through a few locks along the way which was interesting. Apparently the locks can get backed up so the ship's captain keeps an eye on what's going on ahead of him. Don't be surprised if the boat sets said early to avoid a traffic jam at one of the locks the boat has to pass through on its journey down the river. We have been on quite a few ocean cruises but this was our first river cruise.
They do sell a drink package for anyone who likes to drink alcohol. My husband and I aren't drinkers so we passed on that. The price was 300 Euros, which equated to about $325.
We stayed in room 202. The room was pretty small. There were a few stains on the carpet and my husband said the floor was dirty under the bed. The cabin steward kept leaving his cleaning rags in our room so I picked them up and put them in the hallway to get picked up. Another one of their ships docked next to us three days so looking out the window you didn't have much of a view. I don't know if that is the way they normally dock when they are side-by-side, but you might want to book a room on the other side of the ship. The pillows were very flat, but the bedding was soft and clean.
The castle has been spared damage from the wars and is a real treasure to see.