We did research (both online and with friends) before choosing AmaWaterways and it certainly paid off. AmaWaterways is an excellent cruise line with professional, helpful, and friendly staff/crew, delicious food, and lovely cabins/staterooms. Although the Rhine was a bit flooded and we couldn't go on the ship to the last two or three destinations, AmaWaterways arranged seamless transportation by bus. Also, because we had an early flight out of Basel at the end of the cruise and we were not able to dock there due to flooding, AmaWaterways arranged for a beautiful car and drive to take us very very early in the morning to the Basel airport -- about an hour and a half away.
The tour guides were mostly good (there were two who were just so-so) and we enjoyed most of the tours.
I can't say enough about the crew and staff: either they all dearly love their jobs and all the passengers, or they're the best actors in the world! We found them to be extremely accommodating and pleasant and fun.
The cabin was larger than I expected and well furnished. We had plenty of room for the two of us.