We just move in to our second home and this was the first purchase we made for the new house. It is too convenient to no longer need to find a key when you get home at night.   We have in-laws come over and check on the pets without needing to give them a key and we can set up codes for plumbers or handymen to come and fix things while we aren’t at home. Honestly, we won’t live in a house without installing one.