As I said, it depends heavily on the isp you use in China. As you'd be making a direct connection oversea (to US, HK, TW... depends on the server you pick) and if the ISP is shitty, you might not get very good speed during peak hour.
But for Astrill itself, their connections are very fast. On my friend's office in Shanghai (the company had a 500/500mbps connection to their ISP) I was able to reach 40mbps on speedtest.
And if you are signing up, PM me, I have a 25% coupon somewhere.
