Using GMail in China can be very annoying from time to time. I need to use it every day, mostly for communication at work. With VPN there are no problems whatsoever, but as soon VPN is off GMail is first struggling to open (for about 10 to 15 minutes), and after it is opened it will work for like 2 minutes and then "crash" (mail's can not be send, drafts can not be saved and so on).
I really hate the Great Firewall of China. It is not enough to just block services like Facebook, Youtube or Twitter. No, to make it real fun for all the internet users they have to make services which are not completely blocked (and services which are not owned by a Chinese company) appearing to be broken (GMail, Google search engine as examples). Why not disconnecting from the world completely?