Smart devices can testify against you: How home robot data is being used in court
(www.the-independent.com)
I've been playing with my smart home for years now. I'm well past the "oh wow" honeymoon phase and into the "just do your job" phase.
I forgot to mention WAF, Wife Acceptance Factor. Any smart system should fall back to a dumb one, if something goes wrong. E.g. You should never require WiFi to turn your lights on. There should always be a switch that will just work. Central control computer crashes? The wife is annoyed the house is now just dumb, not that the house is now dead.