ELB's HTTPS termination is mediocre and, last I checked, doesn't offer the best ciphers. A year ago It was impossible to get an A+ on ssltest https://www.ssllabs.com/ssltest/ using ELB to terminate SSL.
Not to mention it still needlessly includes a ton of dangerously insecure ciphers just begging to be misclicked.
The current default, ELBSecurity Policy-2014-01 [1] enables ECDSA/PFS and is close to the Mozilla TLS recommendations [2]. Getting an A+ on the Qualys test requires the HSTS header [3], which isn't an ELB issue.
Not to mention it still needlessly includes a ton of dangerously insecure ciphers just begging to be misclicked.