Not really interested in free versions as from my experience free VPN versions are good for only the most basic browsing purposes and nothing else and I have no issues paying something 5-10 USD per month if it means it will work hassle free and without any restrictions. You know the saying, "if something is free, you're the product".
Proton also have the free version, but both Proton and Windscribe free versions are very limited in number of locations, speed and traffic.
Paid version unlocks all locations and they provide unlimited traffic and speed, but for any vpn I would look to avoid jurisdiction of five, nine and 14 eyes countries.
Don't they use residential VPNs for that? I would assume they block any known VPN IP address in their "great firewall".
I remember the days when I ran an open proxy. Without advertising it (it was meant for myself only), it got many Chinese users.
I don't know what exact kind of vpn they use but I know they are using it for accessing twitter, youtube and other websites.
They have their own alternative cloned versions, so I would not be surprised if they have chinese version of bitcointalk forum

It's the cheapest one I've seen if you don't need it continuously. You can literally pay for an hour, and create a new account when you need it again. I just tested it: €0.01 got me 1 hour and 38 minutes of full speed VPN.
Yeah, I was talking about plans that include one or more years, some vpn's even have special lifetime plan deals sometimes.
Getting some deal like that for Mullvad vpn would be great.