We took two separate cruises back to back. Viking simply did not know how to handle this. They took forever to get compatible itineraries, billed us via travel agent for $5,000 in unwarranted charges.
We made our own air arrangements and were told we would have to get ourselves from airport to port of Amsterdam. Met a woman with a Viking sign in airport waiting for others who told it would be cheaper to take a taxi than to join her group. Once aboard ship a staff member told us he had gone to meet us at the airport!
Once aboard ship, everything was five star - food, beverage (free wine with dinners, mimosas at breakfast), smiling staff always eager to be helpful. We quickly made friends with many other passengers.