I am a single lady, British, in my mid-60's and I have just returned from an excellent cruise aboard Amabella river cruise down the Danube from Vilshofen to Budapest, taking in Passau, Linz, Durnstein, Melk-Krems, Vienna, Bratislava, Budapest. I flew by scheduled flight from Heathrow to Munich where several of us were met by minibus and transferred to Vilshofen. Everything including embarkation was very smooth and I even managed to have a late light lunch aboard having unpacked. As the ship was half full, all passengers were upgraded and I had a lovely stateroom with a queen-sized bed, balcony and every kind of convenience ranging from safe, hair-dryer, mini bar and fridge, robe & slippers, umbrella plus the usual complimentary toiletries.
There is a choice of dining either in the main dining room or at the buffet laid out in the main lounge - the food & drink throughout the voyage were of a high standard, as was the service. There is a choice of shore excursions and you can take a more active route, a more moderately paced route etc. to suit individual needs and tastes. The cruise line provided several pleasant onboard evening entertainments relevant to the port being visited.
I was lucky to be able to disembark mid-morning and again, the smooth transfer back to the airport was everything one could wish.