I do not understand as to why you would ever want a 'smart' front door lock. They are not more secure, they are vulnerable to other types of attack. They are no easier than having a key or any cheaper. They are no better VS. a crowbar or a big red key so if someone wants to get in, they will or just go through a window or patio door. Need more keys? Go down Timpson and they will sort you out in a few mins.
Same things goes for kettle, microwave, fridge or oven. They just don't do anything remotely useful yet.
Nest/Hive on the other hand a pretty decent. Anything running on the network has the ability to be hacked.
I wonder how many people will update their routers or even have updates available even though it is widely publicised that WiFi/WPA2 implementations are vulnerable.