smart locks are useful when you airbnb your apartment. otherwise I don't see the use for it.
My running pants came with a special key pocket. Before that I just hung a spare key on an old shoelace around my neck.
There would be a high-entropy emergency password in a sealed envelope hidden in your brother's house in case you ever locked yourself out.
But I don't think the market will produce secure programmable locks at a reasonable price until some government regulator lays down a standard that manufacturers can follow.
Carrying a smartphone vs carrying a smartphone and a key chain.
I wonder which is preferable..