Unfortunately, the device warranty is only two years, unlike the 10 year warranties of the First Alert Onelink and Kidde KN COSM B RF. The Nest Protect smoke alarm is part of the company’s wider smart home strategy, which also includes thermostats, security cameras, security systems and video doorbells. You can also integrate third party devices like fans, sprinklers, lights, locks and more. They all can be controlled through the Nest app. The Nest app isn't the only way to integrate the Nest Protect in a unified smart home, the smart smoke alarm also works with popular third party platforms such as Nexia, Vera and Wink. You can even connect Nest devices to Amazon Alexa and Google Home smart speakers and control them with voice commands. However, the Nest Protect itself doesn't work with Alexa. Nest devices don't work with Apple HomeKit. The Nest Protect smoke alarm has two power options: wired and battery. You can hardwire it into your home’s electrical grid for uninterrupted power, though this option also uses three AA backup batteries in case of a power outage. The battery powered option functions the same, it uses six AAs instead of three, but is better suited for older homes that don't already have smoke detector wiring in place.