Things might be different by now, but when I was researching this I decided on the Yale x Nest.
It's more secure than a keyed lock in the following ways:
- Can't be picked (no physical keyhole).
- Codes can be revoked or time-gated (for example, you can set the dog walker's code to work only at the time of day they're expected to come by).
- Guest codes can be set to provide real-time notifications when used.
- The lock keeps a detailed log of every time it's used.
- The lock can be set to automatically lock the door after a certain amount of time.
It's less secure than a physical traditional lock in the following ways:
- Compromise of a keycode isn't as obvious as losing a key, so you might not change a compromised keycode the same way you might change a lost key.
- People can theoretically see a code being punched in, or intercept compromised communications to use it.
- Compromised app or login could be used to assign new codes or remotely unlock
It's basically the same level of security in the following ways:
- The deadbolt can still be defeated with the same physical weaknesses that a typical deadbolt has: blunt force, cutting with a saw, etc.
- The windows and doors are probably just generally weak around your house, to where a determined burglar can get in no matter what lock you use.
- Works like normal without power or network connection (just can't be remotely unlocked or reprogrammed to add/revoke codes if not online)
Overall, I'd say it's more secure against real-world risk, where the weakest link tends to be the people you share your keys with.