We were on Viking River Cruises......the ones you see the ads on TV about. I think the only thing we would have changed was the air travel. When booking, they present an option to leave it all in the hands of Viking. You choose your preferred departure airport, but times, airlines, connections etc are all up to Viking. When we do another one, I'll pay the extra $100 or $150 to be able to set up our own flights. It's still booked thru Viking, but you have an agent within the company so that you get flight times etc that work for you. You can also use your regular travel agent if you wish. We did all our booking online without an agent. I'd still book online, but do our own air travel.  Outside of that, everything else was just pretty much perfect. Transport from airport to ship and ship to airport, the crew on the ship was simply outstanding, tour guides were all locals at each point of departure from the ship contracted by Viking and were excellent. The food was marvelous, unlimited complimentary wine, beer, soft drinks with noon and evening meals. Everything is all-inclusive except for any optional tours you choose to take. We did 2 and are very, very glad we did them both.  
Email is good if you have any other questions. You'll love your trip, I'm sure.