I heard about PROXPN from Security Now and was a happy user for many years (albeit the connection app was outdated and data throughput speeds were slower than expected). However when their root certificate expired I could no longer connect to any VPN server and this continued for many months, so I switched to another VPN provider and will never consider using PROXPN again. Their connection app doesn't integrate well with Windows 10. After disconnecting from the VPN server, I had to manually change network adaptor settings from static IP assignment (which the PROXPN app does upon connection) back to DHCP assigned IP address to prevent network connection issues later. Also, some VPN servers would drop the VPN connection often and the kill switch simply didn't work on any of my computers.
I have had a "lifetime" subscription for many years and they used to be a really good option and worked well, but trying to go to their website today (2/6/2021) shows that the SSL certificate expired 24 days ago and the client will no longer connect. I guess I'm going shopping for a new VPN provider...
I used ProXPN a few years ago, mainly because it was advertised in one of my favorite podcasts: Security Now! I once had a problem with the service, so I contacted their support. A few days later I got a marketing call from someone in the US (I'm from Europe and ProXPN was the only English-speaking company I had direct contact with at the time). Additionally, ProXPN was the only English-speaking company that had my mobile phone number at the time. This means they must have shared my private details (phone number or even more) with someone. As a PRIVACY SERVICE. Needless to say, I advise everyone to avoid them at all costs. Their business is privacy and sharing contact details of your customers with a third party is at a minimum major breach of trust if not a legal offense in countries with privacy-respecting laws (i.e. not the US). Looking at their website now in 2021 makes them look even shadier: Invalid SSL-certificate and all of a sudden their based in Nevada. A few years back they claimed to be based in the Netherlands.