As firefighter and EMT for the past 20 years, and former 911 dispatcher, Ooma is one of the best choices for safety at your home that is not a TelCo or cable option.
Not all VOIPs do the right thing by offering E911. Ooma does, and just relies on your properly entering your location on their site.
I personally dislike the reliance on cell phones so many use exclusively now. In an emergency, it is not like a TV show. When our center receives a 911 call from a cell phone, and it disconnects without any discussion, we may not have the proper location info. It could be a non-GPS phone... it could have the wrong location provided by the carrier... anything.
If we attempt to call back and they don't accept incoming calls, we can't reach the caller. If the phone is turned off, we can't reach the caller. A real home phone can be reached even if the caller is still on the phone... since the TelCo can break into the line in an emergency. WIthout power, a home phone will work (unless only cordless phones are used).
As soon as the last 1 is pressed on a home phone, the call is already sent to the 911 center. So even if a bad guy disconnects the line then, 911 knows where the call is With cell phones... not a chance. With VOIPS... depends on the service.
Again, VOIPS rely on your entering the proper location. You MUST do it for safety. I remember a dispatch journal article about a woman that called 911 on her VOIP phone to report a domestic. The call was routed to the 911 center in the town she first used the VOIP at, in Ohio. She was now on a military base overseas. The woman had no idea what the MP's or other area PD's direct number was. The Ohio dispatch center called a local recruiter, who got ahold of a superior at the Pentagon. The person at the Pentagon quickly located the base PD. It took about 20 minutes for the PD to get on the scene from the first call. That was not too bad... but think if it was a house fire or cardiac arrest.
Oh... and I do have an Ooma. Love it.