Regularly breaks. What I mean is that, if you log in and enable the VPN upon first installing it works. Then use firefox as normal, exit firefox, open firefox again etc. and eventually the addon will just hang. You click the little icon to manage it and it just shows a loading wheel. Won't let firefox connect to the internet while it sits there broken. The only fix is to uninstall and reinstall the addon which requires logging in all over again. Very buggy.
Additionally, leaks DNS.