This plug-in scanned my site and found some modified files. Two I had modified (plug-in files) and one several others were different because I had installed a brand-new version of a plugin that was not in its master repository. So I understood that.
I was able to customize the firewall rules to fit my needs exactly.
I'm very happy with the capabilities of this plugin, and the guided tour that explained each section of its configuration.
Setup was quick and easy, especially given the configuration capabilities. I also agreed with the default settings - I'll put this on some of my other sites and use it per the defaults.