Readers ....
My wife and I just came off of our first Viking cruise and would like to share some experiences. About 2 weeks before departure our ship was changed from the Vili to the Mimir. The river trip was Budapest to Amsterdam.
Pros:
Luggage transfers to and from the airport to the boat was seamless, orderly and efficent
The food was very good by cruising standards
The dining room staff was phenomenal
The Housekeeping staff was phenomenal
Most of the free tours were excellent
Cons:
Over the last 8 years there has been low water on the rivers (especially in June) .and necessitated us switching ships mid-way through the trip. This is not the fault of Viking obviously, but if you know in advance this is going to happen it would be best to communicate with your guests so they don't unpack and re-pack on one ship and then have to do the same thing again on another ship. This may be the reason that Viking offers such affordable trips during this time of year.
Upon changing ships, no one was informed that the second ship had a non-functional AC system for 36 hours (this was in the middle of a heat wave). To date no compensation has been offered for the inconvenience.
The cabins themselves are very very small.
Several cabins we were in displayed a "sewer gas" odor.
It appeared that the cruise director (which followed us onto both ships) was more interested in announcing upgrading tours than on handling issues directly with the corporate office
As for us as travelers, This was a one and done with Viking. I can not speak for AMA or Uniworld etc.