This was the Roof of the World Tour so the river cruise was just a portion of the total trip. The tour guide for our 18-person group, Jamie, was amazing - knowledgable, compassionate, communicative. She helped us know what was coming and how to be most comfortable, safe and in the moment for each experience.
Our entire experience was first class. The accommodations and food were fabulous.
My major suggestion is that Viking be more upfront about the possibility that altitude in Lhasa could affect a large proportion of travelers so that people were not panicked that their symptoms might have been unrelated to altitude. Fully half of our group required doctor care and we learned that that percentage was not atypical. This was despite following advice prior to travel including altitude medication, hydration and rest.
The original brochure showed a veranda suite for a long ship rather than the boats we used in China. While we made do just fine, the space was less than I had expected.