All in all, this was a very good trip. The ship was very comfortable, the food was good, and the ship?s staff & service were excellent. The tour briefings were thorough and more useful than expected during our rides. The city touring bikes, paniers and equipment were robust and did the job.

However, a very good review with a couple of reservations:

? There was a lot of sailing. The fact that this was an out-and-back trip from Passau to Budapest and back, meant that the ship had to travel twice the distance than if this had been a one-way tour ending in Budapest (approximately 1300 km. vs 650 km). Yes, we knew this when booking and yes, the tour is structured to try and minimize the impact of that much travel. But the net effect - from my perspective - was less time to ride and less time to visit the wonderful places along the way. Our intent on this trip was ride at a comfortable perhaps even leisurely pace to permit us to appreciate the surroundings, stop along the way to lunch or to visit, and not feel rushed. This we did, but at times felt rushed anyway because the ship had an early departure time. In the end, we had a only a couple of hours to visit Bratislava, did not get to visit the Abbeys in Melk or in Dürnstein, and had less than a full day to visit Vienna.

I became curious as to why this tour was not planned as a one-way tour with the following tour returning in the reverse direction. My discussion with the tour director was instructive. The out-and-back tours cater to a European clientele. Typically, more than 50% of the clients are European, many of whom drive to the departure port and bring their own bikes. The out-and-back tours allow them to return to their cars, pack their bikes and drive home - very convenient. Apparently one-way tours are not planned because it is vey complicated to return by train from Budapest ? with your bike ? particularly if there are 60-70 folks trying to do it on the same day. Sounds like a reasonable explanation, but I wonder how that is handled on the unidirectional bike and hotel tours along the Danube cycle path. Perhaps the option of bus transfers with bike trailers could be offered for an additional cost.

? Some mooring locations were not the best. The departure and return dock in Passau was a large gravel parking and trucking yard, quite a distance from the old city and somewhat out of the way, with no shelter available. It appeared to be a re-provisioning dock location for many other river cruises ships, but I did not see any other embarking or disembarking passengers. The dock in Bratislava was at the end of a narrow walkway, fenced off from a construction zone (might be nice in the future?). The mooring location in Vienna seemed to be out of the way, but that may be true for all river cruise ships. The other locations were very good. (It appears that competition is fierce for river cruise ship docking locations, and the big cruise lines have an advantage.)
In hindsight, a shorter out-and-back tour, say from Passau to Vienna, with less sailing time, may have improved our overall enjoyment level. This knowledge will definitely inform my decisions - as a North American visitor - on future bike and boat tours.
Every trip is a learning experience. I enjoyed the Danube Waltz tour and have no regrets. But I do think I could have enjoyed it more.