There’s an active support forum here on this plugin as well as dedicated Pardot support—both of which can help diagnose any issues you’re having. Issues like this are often specific to a given environment; WordPress setup and configuration as well as server configuration all play a part when things crop up. We’re all very happy to help troubleshoot.
My concern about your review is that it starts with “doesn’t seem to work with 4.6”, which isn’t the case. And I’m not sure what the Twitter link was about, as that seems to be about general errors with the Pardot application, which doesn’t have much to do with this plugin, which uses the API.
I really want to help you get set up if you’d like to use the plugin. Please let me know how I can do that.