Newegg sold out of the OBi200 the evening I posted that. I'm not familiar with Ooma. Does Ooma let you plug in your choice of VoIP service provider, or is Ooma its own provider as well as a hardware vendor? The Obihai devices let you choose your own VoIP service(s). Their primary focus is Google Voice, but other services can be added as well.
@sholling is correct that Google Voice does not support 9-1-1. Otherwise, you do get standard calling features like *69 to return a call, *72 for call forwarding, *73 to cancel forwarding, etc. The OBi200 will let you stack up to 5 providers, so you can use a secondary paid provider (perhaps with limited minutes but which allows 9-1-1 dialing) as a backup or for international dialing or whatever. The web interface of the OBi200 contains a bunch of Elvish nonsense, so I assume someone who speaks telephony would probably find the Obihai devices more flexible for their evil purposes.
