I don’t recommend Nest Hello yet, because Google needs to works out kinks, like false positives that suggest someone’s at your door when it’s just a flag blowing in the wind. Also, my unit froze twice in a week, requiring a complete reset. A software update could fix that problem, but there isn’t one yet.
The Nest x Yale Lock is a good product. Since it ties so well into the Nest app, and since it works with Androids and iPhones (unlike Apple’s solutions), it’s one of my favorite smart locks to date. August’s locks are great too, but the app doesn’t let you see other smart home security products or control a thermostat.
If Google fixes the Nest Hello doorbell bugs, it has the best smart home ecosystem for monitoring and controlling your home while you’re away. Until then, buy the Nest Lock and other Nest products, and hold off on the smart doorbell.