We have an electronic lock on the front door and have had a few different ones over the years (and houses), although none are “smart locks”. Every time I read the reviews there were too many reports of people being stuck outside with their smartphone fighting to get the lock to work.
My electronic lock is smartcard/PIN enabled so I get most of the benefits (like not carrying keys) without any of the hassles. While it would be cool to unlock it with my watch or phone there isn’t a whole lot of additional benefits.
When it comes to lights I have had the LiFX ones from the original kickstarter campaign, while they (mostly) worked as described, and from what I’ve read only gotten better, the idea of the primary form of control being my phone just didn’t do it for me. Having to dig out your phone, unlock it, find the app, select the room the make changes it a royal PITA. The smart switches on the other hand negate this problem and mean that anyone walking into the room can turn the light on or off AND you can still control it from your device… As has been raised these are somewhat expensive in Australia and your switches aren’t always in places that make it easy to install.
I think the technology is slowly getting to space where retro fitting these things into houses is becoming more affordable, although often you’re stuck with whatever ecosystem the manufacturer supports rather than any real open standard. It’s still very much a niche product, but I’m patiently waiting for it to become a little more mainstream and a little more standard.