Are combination key lockboxes secure enough for a front door key?

Mechanical combination lockboxes like the Master Lock 5400D and 5401EC are designed to deter casual theft and provide controlled access, not to defeat a determined attacker with tools. Verified-purchase reviewers generally treat them as adequate for sharing access with guests, cleaners, or family, but security-conscious buyers should avoid storing a key to a home with no other protection and should mount or position the box out of obvious view.