I use their stuff. I can’t complain about their vpn. I generally have it on in the background by default and I’ve rarely had issues with speed. And if a server is slow there are tons of others to select from.
They claim they don’t keep logs and so far I haven’t had any reason to doubt that. This is their whole reason for being since the Snowden leaks.
I also use their email, but it’s not my primary email. That’s mostly because of my setup. I really hate web based email so I always use an email client and they offer ProtonMail Bridge that makes it possible to use it inside an email client, but until recently I was running Linux. I think I got fed up with fucking around with Thunderbird and the bridge tool, but I gave up. Now I have a Mac and their tool works flawlessly, so I’m using the ProtonMail a little more.