Hi,
Just an update since Google Voice closes tomorrow. Phone power has been very reliable, especiall at $4/month and has been around for a long time. Again, you can PM me for the additional $10 savings. They offer live chat with great hours and no waits. The price can't be beat (aside from the grandfathered Oooma plan, which you forgot to mention, probably paid $100 for, vs and Obihai, which costs 25-30 on amazon.
A few special features that sets this plan apart from the others:
1) A free cloned line (ask them for details, since officially it isn't offered with the plan, yet it really is)
2) 60minutes a month of free international calling
3)Amazing customer service and the guarantee that the prices won't inflate with next years renewal