The choice of a keyless option definitely depends on how much effort you want to put in & (now adays) one’s technological savvy. I break down the Smart lock into 2 main categories:
On the Hardware side, it seems pretty commoditized: will the device open and close the lock while not draining your battery?
The biggest differentiation comes on the software side: Can it integrate with rental sites, is it easy to use for the Host, is it easy and intuitive for the Guest (especially older Guests)?
You could choose a software company like VirtualKEY (virtualkey.co) that integrates with multiple locks and works with airbnb (as well as other travel sites) to automatically send Guests access valid only for their specific reservation. They will even supply you with the Smart lock to get you up and running.
Being a software company, they can focus all their efforts on making the Host’s life easier: Broad integrations with locks, travel sites, cleaners, & easier key transfers to friends, neighbors, baby sitters, or dog walkers. Even making the app more intuitive for older guests.
If you want to be very “active” and are comfortable balancing reservation calendars, sending access codes, and have more tech inclined guests, there are definitely more options out there. It all depends on what you want to do & how your guests respond.