When I tried it two years ago, it slowed by speeds quite a bit and I ended up getting a refund. So, not quite "the fastest." But, speeds will be dependent on your location and they did say that they planned to add more severs in Australia, which would have hopefully improved the speeds.
As for other VPNs on StackSocial, I'm using BulletVPN and am very happy with it. However, their Windows VPN client is very basic. I constantly get very good speeds. If you don't need a client with lot of features, I highly recommend it.
VPNSecure is half the cost and is also a trustworthy company. I've got a lifetime license for it too, but I had problems access some websites, such as websites hosted in China with it.
I tried Ivacy last year. While I got very good speeds, I found their Windows VPN client to be extremely buggy. Hopefully, it has improved since then. But it was concerning that it crashed very often, on a computer which was otherwise running fine.
Before buying a lifetime subscription for any VPN, I highly recommend that you buy a one month subscription first, so you can see how well it works for you. Depending on your location, what is fast for someone else, may be slow for you or vice versa. In addition to that, with some VPNs, when connected to certain servers, you may have trouble accessing some websites. If you buy a one month subscription, you can test a VPN and see how well it works for you, before spending more money.