I have used a few smart locks (until last year), and I must say the experience has not been anything close to good or amazing. Batteries are drained almost all the time, the lock can sometimes refuse to work.
For Amazon's Key service to work well, they need to have the locks work very reliably. The lock may be the Key's weakest link (not in terms of security, but in terms of reliability).
This has been the opposite of my experience, but that's just an anecdote, go look at the most popular smart locks on Amazon.
I've been using mine for a rental home, and it has paid for itself multiple times over the years by not having to replace keys, not having to call locksmiths for locked keys, and not having to change locks when tenants leave. Why more people aren't using smart locks is beyond me.
Rental properties are a particularly good use case but they're handy in general. Many of us have various people who need access to our house when we're not around--or relatives/friends who we want to give access in case of emergencies, etc. It's nice to just be able to given them a code. Keyless entry more broadly is also nice because it means one less thing (keys) I need to take on trips when I'm not driving.
Nice. mine were initial versions of Lockitron. And then an August(didn't have much patience to test it, so returned it). Haven't tried Yale Z-wave (is it standalone? or is it bundled with a security service?). I'll give it a try when I move next time.
Yale and Schlage seem to be reliable (Dad has used both, his rental agency prefers the Yale on all homes for consistency).
Z-wave and Zigbee are two of the common home automation protocols. So, you'd use those locks (or other devices) in conjunction with an automation hub (I use Samsung Smartthings, Dad uses a Vera). Some will also integrate with the Nest system or Alexa, but I'm not sure if that's directly, or via one of the hubs I mentioned.
You can build your own "security" system with these. Quotes because adding cellular/phone support isn't usually directly supported, though there are ways to hack it together.
I have mine set with timers, motion sensors, a Nest thermostat, and light switches. I'll add cameras eventually - waiting to see how the Nest video doorbell works out (if it's good, I'll likely cough up the money and go all Nest camera).
I have a Schlage on my house, and just changed the batteries (4 AA) after a year. They read as '60%' in SmartThings, but they were getting sluggish. You could hear that it did not have enough torque to do its job as well.
I have used a few smart locks (until last year), and I must say the experience has not been anything close to good or amazing. Batteries are drained almost all the time, the lock can sometimes refuse to work.
For Amazon's Key service to work well, they need to have the locks work very reliably. The lock may be the Key's weakest link (not in terms of security, but in terms of reliability).