You should also check out the Trustworthy Internet project report on SSL/TLS deployment quality.[0] The big increase in B and C grades this month (compared to last month) is due to Qualys's SSL Labs tester becoming more strict about DH parameter size (less than 2048 bits caps your grade at B; see also Logjam), lack of TLS 1.2 support (caps your grade at C), and RC4 deployment with TLS 1.1 and 1.2 (caps your grade at C, RC4 deployed for TLS 1.0 still only caps you at B).[1]
[0] https://www.trustworthyinternet.org/ssl-pulse/ [1] https://community.qualys.com/blogs/securitylabs/2015/05/21/s...