I don’t use it often, but it’s always worked fine when I do use it. And it works on my PC, Mac, and my iOS devices. I use the OpenVPN client on Windows and iOS and Viscosity on Mac. PIA has its own client for PC, Mac, and iOS, but I like using a standard third-party client instead. (I might try their iOS client at some point, since OpenVPN on iOS is a little wonky.)
Things have worked out well enough that I wanted to renew the subscription, so I had to enter new credit card details, since I’d used a virtual card number the first time. I almost gave up on that, though, since I couldn’t get their credit card update form to work. I opened a support ticket with them, and they gave me the usual advice to clear cache and cookies, but also to fill in the form by hand. Previously, I’d been using 1Password to fill in my card info and address. Well, it worked after clearing cache and cookies and filling in the form by hand, but it was a pain. When you’ve added so much awful client-side code to a simple form that it won’t work without forcing the user to jump through a bunch of hoops, you’re doing it wrong.
But hey, they were helpful, and now I’m signed up for another year.