I second this. I can't make any claims about the security of the client, but the way they handle things is confidence-inspiring.
I have been in touch with them over some issues I have had,and the support is fantastic. I had an issue with mosh over my local network (SSH worked,mosh did not) and got a very detailed reply about why they treated LAN UDP packets that way, and why I was probably not affected since I ran a modern Linux distro and of course the setting that turned that safety feature off.
And, if you do t trust them to make such decisions for you (or you run an unsupported OS) they have regular openVPN files
They definitely aren't just running a VPN to make a quick buck. The amount of guides and such that they offer for integration, etc. is confidence-inspiring as well.
What sold me was their mention of using Qubes OS in-house. They clearly give 100% fucks about keeping their infrastructure safe.
You can generate unlimited free trials until you're confident you want to spend the paltry $5 a month on them.
https://mullvad.net