I have four of them, purchased from Amazon. One Nest Protect was DOA (wouldn't connect to wifi) and Amazon had a replacement to me next day. They work flawlessl

I have four of them, purchased from Amazon. One Nest Protect was DOA (wouldn't connect to wifi) and Amazon had a replacement to me next day. They work flawlessly: they work when I test them, don't make noise when they're not supposed to, they do a quick sound check once in a while, the quick "flash green when you turn off the lights at night" to confirm things are ok is great, and the motion-detecting night light feature is handy in my hallway, too. I'm a big skeptic of most things IoT, and I agree with most points in the posted article, but my honest experience is that my Nest Protects work great.