Sounds like a good deal, but the thing which has always made me weary of these kinds of services is that 911 just doesn't work the same with it. I have a traditional land line, I dial 911, they immediately know my location before even answering my call. I make a 911 call with my telephone, GPS coordinates are sent, and they still can find where I am. VOIP 911... just not the case.
If you're interested:
http://www.fcc.gov/cgb/consumerfacts/voip911.html
Even if they manage to figure out the location problem with VOIP 911, there's still one major drawback to it compared to a traditional landline:
Traditional telephone will still work if the power goes out. VOIP won't.
I'd stick with a regular phone.