This was our second Viking cruise, we previously did the Rhine cruise. You can't go wrong with Viking. The level of service and quality of tours is really amazing. The itinerary for the Danube cruise is a great mix of large cities - Budapest and Vienna - and smaller towns - Passau and Regensburg. The beauty of a Viking cruise is that you know you'll see all the sights in each port and enjoy amazing service and food in between. Highly recommend the Bavarian Beerfest optional tour in Passau. If you are on the fence about a river cruise with Viking....just do it, you will not be disappointed! Its a great trip to take with other couples, we are in our late 40's/early 50's and although we were among the younger onboard it still was just right for us. You can customize your experience with the different levels of tours they offer, and how you chose to spend your free time.