Well, I jumped in and bought it. Earlier this year my wife's work computer was hit with RansomWare. It's not pretty.
My intention was to use it to whitelist processes allowed to interact with my most important data. That's variously stored in D:\Project, P:\ for my photos, etc. But as far as I can see in WinAntiRansom, you can only designate one part of the filesystem (a non-root, non-virtual directory) below which everything is protected. That means I can only use it to protect *one* such area, not all of them. And that makes it almost useless.