The entire Roof of the World tour included a land package that started in Beijing, then we flew to Xian, Lhasa Tibet, and Chongqing, where we boarded the Viking Emerald and sailed down the Yangtze River to Wuhan; then flew to Shanghai, where the main tour ended (but we also took the post-extension tour to Guilin and Hong Kong). I will not give a full review of the entire trip, as this posting is primarily about the 'cruise' portion, but for more details on the rest of the trip, I recommend you read the review by terran_explr, 'Perfect way to visit China', although that trip (Imperial Jewels of China) did not include Tibet.
I will also note to you that if you take the tour the first week in October, be prepared for massive crowds at all the tourist spots, because this is their national holiday week, and the Chinese are also on vacation!
First, I will say that the tour escorts Viking provides are first rate. And our guide, Arnold, was the best of the best! You will be very lucky, indeed, if you get him for your tour. And I must also say that all the hotels we stayed at were first rate (4/5 stars). We stayed at a couple of Fairmont Hotels and the rest were Shangri-La Hotels; all were fabulous and luxuriously appointed. Dining in the hotels was usually buffet style, so lots of choices, and good food. Other restaurants during the day's tours were sometimes 'uneven' in quality; most just okay. Although I will say that the restaurant we went to for Peking Duck was exceptionally good!
Nicely furnished room with veranda. Enough room to move around in and adequate storage area. Bathroom is about average size for a ship, though nicely appointed, including hair dryer. Bathroom & room attended to daily (always had fresh towels and toiletries). TV and music available. Everything worked in our room, so no complaints.