[VoiceOps] RFO: Cisco ASR platform as an SBC

All, I was wondering who out there has actually used Ciscos ASR platform as an SBC and what are your opinions of it? I am well acquainted with the offerings from Acme and Sonus but I have a specialized need that those vendors may be pricing themselves out of in licensing, but it MUST be a B2BUA which eliminates OpenSIPS/Kamailio as a potential solution. I'm also looking for a solution that can be scaled out to between 16k/32k sessions/node with high availability and media handling, but with minimal signaling mangling and transformations. Please feel free to share your experiences good, bad or otherwise. Thanks in advance! -Ryan