We really enjoyed our self-guided bike trip to Budapest. All the logistics were handled without any hitches. Our luggage was always waiting for us at our hotel each night. The bikes we rented were near new and well tuned and very easy and pleasant to ride. We relied on the Radreise Freunde app for maps and points of interest. Apart from a few bugs in the navigation, it worked great and the EuroVelo 6 was clearly marked.
The only negatives worth noting are that parts of the EuroVelo 6 were not paved which required us to ride on some buys roads which was unpleasant, or ride on gravel paths or even muddy tracks (for short periods). Each town we lodged in was charming in its own way. But there was not much to see in between destinations. So each day it was about biking and getting to our stop. One note to bikers, the EuroVelo from Vienna to Budapest is not shaded. We had a week of very hot weather and the sun was very intense so plan accordingly. Other than that the routes are flat and easy to ride, even with some of the longer distances.
We had once instance, in Gyor, where our hotel was not a "usually contracted hotel" and was 10kms out side of the centrum that required biking through some busy industrial areas and roads to reach our hotel. And we would have had to ride back into Gyor another 10kms the next day to start the ride had we not insisted on the tour operator driving us and our bikes to the start of our ride. Most unfortunate was we did not get enough time to explore Gyor which was the nicest stop on the tour.
The tour coordinators were all very responsive to our needs and helped with any coordination issues we had prior to, and during our tour.