I'm not sure what you have heard... but they have improved over the years... The last time I flown a China-based airline was in August was with China Eastern and the last time I flown Air China was in 1998. All are in cattle class.

I don't have any good stories but maybe a list of what to expect with chinese Airlines might be more useful -
(1) Some FAs cannot speak proper English, and they don't smile.
(2) There is no entertainment except some funny cartoon. Hence, bring a book or your own CD/DVD player or any other entertainment
(3) Food wise is actually okay out of their stations that are NOT in China. I assume you would be flying back to SFO from China. My experience with this was when i was flying back to SIN from PVG, and they gave us a lunch box with some cold food and a hot dish on the side, rather than a proper tray, and this was dinner. Maybe might be useful to bring some snacks just in case you are not used to it.
(4) There might be a lot of carry-on luggage. More than 1 piece per person.
(5) Not sure if toilets are cleaned mid-flight. So they stink. But so does the toilets in BA. They stink too.

Can't think of anything else, but these are based on my own experiences. Will write more when i remember.