ChrisWalker said:
I don't see how polling vs. live status would change the reliability of Z-Wave, though.
Chris
It does not affect the reliability of Z-Wave, but might affect the reliability of the HA system if the main controller (per instance, the Elk M1G) thinks that a given device is off, but it is ON because of local control or because another controller was used to turn it on. Since the controlled Z-Wave device only sends the "live status" to the controller sending the command (and not the M1G), then the main controller misses the actual state of the device. The same happens if you want to get the state of your appliances/lights via internet. In this situation polling (if your number of devices is not too high) is the only alternative.
All depend on the logic of your HA system. For human or computer
remote control Z-Wave's implementation of live status is perfect. For a smart
home automation system or for web control (were others at the site can make local changes) only a protocol with peer-to-peer live status notification would work.