I would be willing to say that it may not matter. When I was touring China, it was 1985 and there were only a few hotels in Beijing. Now there are hundreds, and with the Olympics fast approaching, they're all spiffed up and on their best behavior. Everything should be excellent.
Xian may be another matter - probably much fewer hotels there, and more limited food. However, I'm sure you'll have a great time despite any drawbacks. Our hotel in 1985 was adequate, and when the food turned out to be not too great, the whole tour group took over the hotel lobby for an impromptu party with snack food we all had tucked away in our luggage.
Since the river ships are fairly small and only have (I think) three passenger decks, the few feet between decks shouldn't make too much of a difference in the view. If it does, go up to the top of the ship and grab a deck chair for the day...
I'm sure you'll have a great time. In Beijing you'll probably visit the Forbidden City, the Summer Palace, the Great Wall the Temple of Heaven, and maybe the Ming tombs...all are awesome. My tip for the Great Wall...find out how long the tour bus is there. Get on the wall, walk up the wall for half that time (to get away from the crowds), then take pictures and head back down.