Hi there, love the concept of the plugin and I've been trying to get it to work on a clean test site (no other plugins, 2013 theme). Google+ comments work in both directions (comments on the site appear on Google+ thread and vice versa), but Facebook comments are not.
If I post a comment on my WordPress site, it will appear on the Facebook post, but if I post a comment on the Facebook post, it will NOT appear on the WordPress site. I have tried clearing cache, different browsers and even different machines on different networks. No luck.
Additionally, if I the WordPress article to a Facebook page, I get the same behavior as above AND any comments made on the WordPress post, are not sent to the Facebook Page but rather appear in the user (mine in this case) Status page.