The idea with this plugin is great but this plugin doesn't work. The few ties it's generating files it's saving them in a folder like /wp-content/plugins/really-static/static and redirecting your entire blog to that directory. Who want to have a blog like that?
The S3 upload isn't working either. Nothing is uploaded at all.
The error messages you get are poorly written, but in most cases completely impossible to understand. You need to know German to at least understand a little of this plugin.