Hello, great work for this plugin. It is really fast!
I have a problem with WP Super Cache: although the pages load, I get a 403 response on the site root. See this analysis:
As the site loads ok, something might not work because of this. The first things I could see not working are the reports of Pingdom & Montastic with site uptime.
PS: I also use 5G protection for .htacces (http://perishablepress.com/5g-blacklist-2012). I removed it and still got the 403, so I would guess it is from WP Super Cache. As far as I know, the server runs suphp.