Great VPN overall. I've been using it for years and it woks smoothly, all the time. It gives all that it offers.

Also a plus is that it works nearly for any platform/OS out there. For example, I use Linux as my main OS and they have a CLI app for managing the VPN as well as extensions for all of major browsers.

It's just all you need of a VPN client.

In regards to the Firefox Extension, as well, it's works great.