Viking did their typical great job of organizing and running a three week Roof of the World visit to China. Can't really complain about anything. The food was great. The guide we had (for the entire duration of the trip) was excellent and really worked at getting all the guests to talk to each other.
The food on board was very good. You had the choice of Chinese or non-Chinese food which helped alot. Food on the land portion was also very good. The hotels were all 4 or 5 star and mostly had buffets which allowed you to choose again from local foods or more standard European/American offerings.
The cabin on board was ok but not stellar. Internet while supplied was virtually useless. The guide offered a mild apology in that Viking does not own the ship. They will be bringing their own boat online in a year or two.