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.