An H1B doesn't have to reapply for a work visa every year, and they eventually get a green card, while green cards are extremely rare in China. Also, you don't have to re-register at the PSB in the states a few times a year, waiting in line just to get a little slip of paper.

It is easy to get a working visa in tech, that's for sure, and if you have a company that jumps through all the hoops for you, it can be relatively painless.