I have been with Anveo ever since I started with the OBI100--nearly 4 years ago. I would largely echo the comments of bGood above. Especially as it relates to support. I am not sure they offer the exact services I have anymore. I pay them $1.80 per month--80 cents is for e911 support and $1 is for a phone number. The phone number is for fax handling which my wife thinks we need. So, it is our fax number. Upon receipt of a fax we get an email notice and a pdf. Once I got it configured it seems to work fine.
In the recent 'TCP Backing Off' error where the OBI100 quit working, Anveo worked perfectly as a backup. I had to change GV to ring my cell but Anveo made outgoing calls flawlessly. I see that I was charged a half a cent for all outgoing calls on my plan. I don't know what I am charged for incoming calls. I don't think there has been any charge for the few fax's I have received.
Who knows if Anveo will be around next week? But, for now it is very reliable and as near as I can tell a full fledged, full featured VOIP provider.
I think you can get some integration with GV contacts but, could be wrong, I don't think Anveo can process your GV number directly. Now, you could always have GV ring your Anveo number :-)