Agree with pontac assessment. Use google maps to see how far some of the paid excursions are from the ship. Easy to enter location as Viking dock Vienna, for example, to Saltzburg. With traffic it can be a 2.5 hour commute each way. Viking buses are very quiet and comfortable. Ride up to the Black Forest was very scenic and I enjoyed the small hike we did. Skip the Rudesheim restaurant excursion! The food served to the group was inedible. While customers around us were ordering off the menu and getting fabulous dishes. Tiny town, go to the restaurant on your own reservation, you don’t need to be with the group. Ask Viking front desk to make reservations for you. Short pleasant walk.
Be aware when description says “time on own” it’s very limited, they don’t want you to wander far from them. There’s nothing wrong with this scenario if that is your touring and mobility style.