Thanks for finding this. Calomel's website [1] gives much more information about how the scoring is done as well as security in general; very interesting.
Also the Netcraft Extension gives you this information:
http://news.netcraft.com/archives/2013/09/06/perfect-forward...
I found "Calomel SSL Validation," which I am about to install. The PFS reporting only works with Firefox 25 and up.
https://addons.mozilla.org/en-US/firefox/addon/calomel-ssl-v...