There was some noise about the GFW doing clever stuff(tm) to identify VPN traffic and punish the local IP for that. Was that real or hype?

That's definitely real. Normal, unobfuscated VPN will result in packet drops after a couple of minutes. Even obfuscated VPN will trigger packet drops if you send too much traffic.

It depends on the protocol. Unobfuscated OpenVPN definitely behaves in the way you describe. But I very rarely have problems with PPTP, which is unobfuscated.

Thanks for that - it's great to have a confirmation. Obfuscated/unobfuscated VPN traffic, what is the actual difference at protocol level?

Put simply, AFAIU, it's the pattern of TCP packet sizes. OpenVPN, for example, has a very recognizable handshake that makes it prone to detection. This post goes into some of the network-level details (not OpenVPN-specific): http://blog.zorinaq.com/my-experience-with-the-great-firewal...

Try shadowsocks it designed and made by China :-)

https://shadowsocks.org/en/index.html

I agree, shadowsocks is much more powerful open source solution in crossing the GFW. But I’m hardly find a quick reliable service provider. And the primary developer (a young woman) quitted under the stress of administration. So the future of this project is unclear.

But its a game of cat and mouse with which VPN providers are currently blocked.