I just found obivoice a couple of days ago. Signed for a 30day trial and did lots of testing. I would say I really like it and will sign for the two years contract.
There's no quality problem except some delay but not too bad. One feature I like is number spoofing because I would like call out use different method but incoming call come to the same place. This is one thing I don't like GV in the past. Auto configure of obi devices works fine, except for one small glitch, which has been fixed. I tried different devices and programs, e.g., Linksys ATAs, asterisk, csipsimple and etc. Obivoice just behave as a standard SIP Voip service, which is not the case for MagicJack, Ooma and nettalk duo. I can even receive calls on my Android phone using csipsimple but haven't tested much yet.
In any case, I feel it is an ideal replacement for GV, at least for me.