I bought a Obihai as a backup to my Ooma. At least it still will work with some cheap options.

I started with Vonage. After a few years of the bills I went to Ooma. Been using it for a few years and I love it. It's sync'd with my GV and I have no issues at all.
When my ooma broke (power outage and brownout killed it) I had to wait a month+ for my new one from the USA (before I could go get it) and I picked up the Obihai for cheap. I was quite pleased with it.