After a bad experience with a supposedly market leader then tests with two other VPNs, I eventually choose SurfShark and presently use it on 4 Linux and 3 Android devices. Overall a very good VPN, although the number of servers worldwide might be improved...

I downloaded this add-on after paying for a 3-year subscription to Surfshark but quickly realized it wouldn't work for my needs. I contacted customer service through the live chat and, after a few simple questions, Mia issued me a refund within 24 hours. Very happy with how they treat their customers.

the addon does not reconnect to the proxy when the browser is restarted, even though it appears to have been connected, when viewing the UI. A forced disconnect & reconnect is required to regain access to proxy, and "CleanWeb"

using Surfshark on linux sucks, the service works very well on android and windows, but on linux is a lot more insecure, inclusive when I make tests on the official page, the result is that there is a DNS leack and the solution is buying the service, but the funny thing is, I already have the service activated.
And when I use chrome extension the leacks dissapear but on firefox extension I can't even access the account. The service has potential, but it needs a lot of improvement to work properly on linux.

Surfshark has excellent working apps for Windows and Android giving great flexibility, control and put the whole system behind the VPN not just the browser. I gave both of them 5 stars. I expected the same with Linux but it refuses to install and I want my whole system to be behind the VPN not just my browser.
PIA gave me all of the above but I gave it up because it was bought by a company that made its money creating spamware and then sold itself to Kape Technologies, Kape mainline of business is creating spyware for any government willing to buy its services. I must say that Kape has a dry sense of humour as it promises it will protect the privacy of its users (and will respect them in the morning?). Check the link below:
https://www.hackread.com/private-internet-access-pia-vpn-sold-israel-privacy-concerns/
I want my PC to be entirely behind a VPN not just one browser.

Relatively easier to connect compared to the standalone Win app, lessening connection error and downtime. However, lacking more comprehensive options such as the Kill Switch.

I have reported to their online chat that their addon is leaking WebRTC but they insisted tested on ipleak.net which is fine. Worse still it reflected that it even leak on their own webpage for WebRTC test site. No details follow up to which i have urge for an updated to resolve it. We paid for privacy and it has even went through the security audit lately published on their webpage. Find it hard to accept it.

When I sign of for a VPN, Firefox add on should not block it

Ne fonctionne pas, refuse de se connecter à mon compte.
Doesn't work, refuse to connect to my account.

Ne se connecte pas...