I wanted a cruise of at least 2 weeks and a mixture of large cities and smaller towns. The churches, abbey, palaces and windmill interested me. The cost seemed reasonable. I had previously visited Vienna and Budapest and looked forward to going back. The scenery was overwhelming; just sitting on the boat looking out the windows was worthwhile.
The meals were fantastic, often with foods I had never sampled. Breakfast and lunch featured buffets, but there were also menu items which could be ordered. I enjoyed the unlimited wine at lunch and dinner.
Often there were evening concerts or lectures. Classical music, opera, pop music, and folk music were offered.
I loved being in the cabin and looking out. The only missing feature was a chair. Maybe you could provide a folding chair in the lower cabins.