OT? cRTP header compression

I'm looking for real world experience related to deploying cRTP header
compression on Cisco routers related to VoIP flows. We are trying to
evalute what type of hardware (ie: CPU power since cRTP is CEF switched
since 12.2x IIRC) is required to handle 96/192/384 VoIP calls over a
single circuit (HDLC/PPP/FR). This is related to specific overseas
circuits where the cost of the circuit is still very expensive vs the
cost for the extra hardware to handle the header compression. I'm
disregarding all QoS info at this stage.