Very true. Haven't tried it myself. But definitely worth it.

Never heard of Astrill, but I've never had issues with PIA (Private Internet Access) using OpenVPN or (now) Wireguard on iOS, macOS, and Windows 10. I also run a VPN server at home, in case countries like China have blocked all the IP's of the major VPNs.

It's been almost 3 weeks since I signed up for Astrill and my frustration with the service is through the roof. The service keeps disconnecting after the screen is off for a period of time. I've already added Astrill to a list of services to be exempt from power conservation and this behavior still exist. Sometimes, the app and the VPN icon is on, but nothing works. The only way to restore service is to disconnect and reconnect.

I think you mentioned in a previous post that you signed up for a single month. I'd suggest just looking for another provider at this point based on your frustration. Maybe go back to ExpressVPN as they seem to be the most active in trying to evade the Great Firewall and if you're concerned, maybe get NordVPN or PIA as a backup (although in theory all three could be blocked at the same time).

As mentioned previously, if your router supports it, maybe set up your own VPN. Or if you're proficient in Linux and have a RPI lying around, set one up using that. Or (last one) you could set up a free account on a cloud provider (maybe not one of the big boys, but someone like linode.com which doesn't entirely charge by transfer) and set up a VPN (in theory you could repeat the process every time you go to China as the free accounts usually expire once their credits are all used up).

If it's just bypassing geoblocking, then setting up your own should do the trick. That said, some advice I would provide (take it or leave it)... if your "modem" (DSL or cable or whatever) supports plugging in multiple routers (imagine NAT going wild), then I would have a dedicated router with nothing else connected to it as the VPN host. Segment your network to prevent exposing other endpoints in your home/office to the VPN. That way if it becomes compromised, the other endpoints in your house are somewhat protected (in theory).

How do you know that they're still working on it?

Take a look at some of the Youtube vloggers that vlog out of China (and are critical of them). That'll give you a general idea.