Ни одна версия так и не заработала на firefox 56, что самая последняя что более старые, очевидны проблемы с оптимизацией, после установки и входа в аккаунт полностью блокирует интернет соединение браузера, изменение настроек не меняет ситуацию.

No version ever worked on firefox 56, which is the latest, older ones, problems with optimization are obvious, after installing and logging into your account completely blocks the browser’s Internet connection, changing the settings does not change the situation.

The best thing is the generous free monthly 10 GB traffic allowance which you get by signing up with your email.
I installed WS desktop+Firefox addon on two notebooks. On the rather new HP250G5 with Win10x64 Home the install went without a problem. On the old HP 6715s with Win7Ultimatex64SP1 it took some fiddling to get the desktop program connecting with a WS server. As this depends on many factors like the load on the servers, your connection and your setup I don't blame the good people of WS.

Next I tested WS for DNS leak and WebRTC leak on TorGuard, tenta.com and privacy.net. While these sites didn't detect a DNS leak my local IP was leaked by WebRTC. I recommend using WebRTC Leak Shield addon for Firefox.

I used Tixati torrent client with WS and had good download speeds. How good WS is in unblocking streaming services I can't say.

With their build a plan offer you pay $1 for one location per month and get a modicum of privacy with unlimited traffic.
Techradar ranks WS 7th out of the 10 best VPN services of 2019.

Es perfecto!!!

Great addition to my browser; stays out of my way, works well, easy to use and the first 10GB is free!

great VPN, I get unlimited use, a few select countries and one country of my choice for $2 :)
build a plan is totally worth it if you want to protect your phone/desktop apps and/or just your browser ^_^

Works as expected, I have no issues with it.