I have no specific experience with China, but right now I'm not sure I would consider it. I know of people who have spent time there (much like some of the other posters) and on the other side I have been acquainted with people that "escaped" for being labeled one thing or another by the government (they certainly had some frightening stories to tell).
"It was very safe when I lived there... people are friendly... I wasn't afraid" are great... until the stuff hits the fan (for one reason or another). Suddenly all those great things dry up, and as a foreigner you'll find yourself with very few if any friends, and little to no recourse (if you think they normally have few rights... you will have none)... and depending on where in the world you are, being a from the U.S. could very well be to your detriment (particularly if they think you are worth something).
Over the years it seems my biggest determining factor on foreign travel is what you wouldn't normally notice... and what you probably wouldn't want to notice. Things like...when you get off that plane as a tourist/job/etc., you might not see that the guys flying aren't even allowed leave the plane... they'll be lifting off to get out of the country ASAP, as their safety is considered to be in jeopardy.
Then again there are states in the U.S. I am starting to think about avoiding in the currently political climate.
