The folks at XTEN and Broadvoice were kind enough to help me sort out configuring the awesome SIP softphone, Eyebeam with the BroadVoice service. Having been on the road for over ten days in broadband enabled WiFi hotels all over France all I can say is the combination is the VERY BEST softphone/VoIP experience I have had to date. Easily on par with SkypeToSkype, the call quality has been pristine and in most cases people I have been calling have not known I'm on a softphone or in Europe. That's the acid test.
Eyebeam is a significant step up from the X-Pro or X-Lite clients I previously tried from XTEN. Those improvements and the well engineered BroadVoice network makes for a seamless conversation process.
All I can say is if you're a road warrior like me, this allows you to not have to travel with a Telephone Adapter and if you're in good WiFi locations and use a solid headset as I do (The Plantronics DSP 100 that Tom Keating first suggested) then you have the makings of a very useful, portable phone system. I don't know how much more one needs.
The only rub has been when I fire up my HotSpotVPN, which seems to disrupt things. I plan on getting XTEN and HotSpotVPNs Glynn Taylor talking as their has to be a fix possible. It's just software. As for BroadVoice, they have rapidly become an easy to reccomend provider, in the same league as CallVantage. Their quality is superior to Vonage, and they provide incredible support. That, and they're very nice people to boot makes them the kind of company that's hard not to like.