What gets leaked depends on the quality of the service you use, the country of origin of said company, and what kind of activity you are up to, should you be using the VPN and there is a leak somewhere along the tunnel.
Also PIA claims not to log. That's a big deal. Weather or not that's true no one knows. There are also ohers that claim to be totally Anon. Depending on where they're located can cause concern, like the 5 eyes. look here for the best VPN's https://torrentfreak.com/vpn-anonymous-review-160220/