Has anyone here had success with USB fingerprint scanners?
I also found this Microsoft keyboard with fingerprint reader but I don't know if it works with linux.
For simple PC unlocking etc. they are perfectly fine and improve security due to their far higher usability.
The same way 10 key files on 10 different locations combined with this and that are more secure than a simple 60 character password. But the simple password is far more practical, so far more secure overall since people actually use it.
For most people, the only security they really need is against people either stealing devices or accessing them without permission. In those cases, biometrics (if implemented properly) and passwords are roughly equivalent.
More secure legally. You generally can't be compelled to disclose a password that incriminates you (unless it's already apparent that you're guilty of wrong-doing) but a thing (physical key, fingerprint, etc) isn't protected in the same way and can be demanded by the court.
Whether biometric are secure or not is another question, they can be stolen like any other data or a motivated attacker could just take you or your fingers.