1. Company registration - rules for company registration for all kinds of incentive zones keep changing monthly. That's insane.
2. Property protection: state has to give assurance that the 2009 style purge will not happen again
3. Personal safety - Shenzhen beats most cities in US on that, at the price of having a police post every 100m
4. Freedom of movement - you have to apply for 3 visas beforehand HK visa, China visa, Macau visa. APEC card works as a universal visa, but god know how one gets it. Last time I applied, the chamber of commerce said it is first time they heard of it.
5. Lifestyle - Shenzhen is one of world's most livable cities already, a head above of Silicon Valley
6. How much money you can make - not enough for somebody working in SV,or London already. A senior engineering cadre nets 25k-30k CNY per month. Cost of living, 7.5k CNY for a bachelor, even if you party hard. So, in the end you get around 3k usd to spare at current CNY price. I don't see much Americans, but for Eastern Europeans... 9 out 10 white people you see in factory districts speak Russian, or some other Slavic language. Lots of Indians, and Africans as well.