If you want our opinion on the quality of the feature I would say it works well. Like any other VPN session it can occasionally drop and as with any VoIP conversation the quality of the voice is highly dependent on the quality of the network between the two locations.
We probably have several dozen locations with VPN Phones at this point and all are working well.
Kyle Holladay
ACA-I, ACA Call Center, ACS-I, ACS-M, TIA-CTP, MCP/MCTS Exchange 2007
ACE Implement: IP Office
"If it worked the way it should you wouldn't need me