Here are descriptions of the more relevant changes in EVSS  15.0

PrivateWave changes

This version carries a User Interface redesign of clients and server, plus many new devices and OS version support.

PrivateServer changes

SIP Trunks Integration

Despite SVoIP (Secure VoIP) protocols used, some PBX do not grant security, eg:  PrivateWave  =>  PrivateServer  => SIP PBX => GSM device in clear. This call is a crypto-to-clear scenario and there is no way to notify the unsecure call to the caller. These PBXes can now be marked as untrusted: before bridging the crypto-to-clear call, both participants will hear an audio security disclaimer warning them that the call could be not  secure.