This is an interesting article since it is actually referring to the safety and reliability of the smoke detection, however much of the essence of the post could easily be applied to cybersecurity. It even refers to 'false alarms'. What I wonder is if Nest has addressed some of the system security issues discovered by researchers recently?
There's nothing cool about safety. Yes, safety is important, but it's very rarely cool. The stylish Nest Protect is, at its core, a smoke detector -- the least chic item in your home. Still, when the company that brought us the smart thermostat introduced a smoke alarm, it stood out from its rivals with swanky features like lighting your way in the dark and a companion app. Those were and still are nice, but it's the safety features that make the device a worthy addition to the home. In particular, Nest recently updated the Protect with more precise air detection. This is a welcome turn after the company's wave-to-silence feature in the last model ended up accidentally silencing the device.
http://www.engadget.com/2015/09/16/nest-protect-review-2015/