For native Control4 Zigbee the module is special and has to be bought with the lock from Control4, added middleman, yup costs more. And then lock only works with Control4; maybe that's more secure than zwave or the cloud, personal choice.

I also prefer buttons to touchscreens. Much easier to press, works with gloves on, easier for long fingernails, and more resilient and less fingerprints/smudges left behind. Use different codes for different family and distribute the digits throughout so all buttons used periodically.

As to backup, have at least one door to the house work with a physical key also so if batteries fail, or gremlins, there's old school access. If they don't want to carry a key, keep it in the car, hide it, whatever.

We've needed both companies for device support, both equally helpful/responsive.