We have taken Viking river cruises before and found them to be very good and the staff to be very accomodating. Many time American tourist expect too much. Every cruise line is going to buy the cheapest airfare, what do you expect, You are paying less than the Apex fare. The food was very good, not as good as many Ocean Cruises, but the stall and passenger load is smaller. We found the tour and guides to be excellent.
They were all locals, knew there tour well, and maybe, gave a canned presentation, but what do you expect, I would do the same if I led a tour every week. We were able to leave the boat, any time and do our own thing, as you will likely be able.
My advise is, your on vacation, not every thing is going to go as you would like, but relax and enjoy.