I'm a developer currently living in China and working for an Australian company. It is immensely difficult to work here without a VPN and I notice it in every part of the work. Searching the internet for information about a problem is nigh on impossible, Google searches are intermittent, I can't access a large amount of developer blogs, and stackoverflow is intermittent too.
One funny one I came across last night was after installing Mint. The Ubuntu repos aren't blocked, but the main Mint repo is. Luckily there is a Chinese mirror that is actually really fast.
I'm lucky in that I live very close to Hong Kong (I'm in Guangzhou), and VPN access to Hong Kong is blisteringly fast. I keep VPN accounts with both SuperVPN and StrongVPN (when one is performing poorly, I switch to the other). From my experience, SuperVPN has the better performance in HK.
I love living in China, it's an amazing country with some great people, but you really need to be prepared if you want to live here and work in IT internationally. Make sure you organise a VPN before you get here, and always have a backup plan.