I did an 8months stint doing some data modelling at a Chinese start-up in Beijing.
Visa was difficult but company culture there really respects people who are experienced and innovative. Most the workers there aren't really passionate about what they do (From my understanding, most Chinese startups don't give equity to their employees)
English is a huge advantage as we have access to an awesome global community of people.
Pay is surprisingly good, but living cost in Beijing is deceivingly high as well.