I don't like using fingerprints because my fingerprint is literally left on the reader. Anybody with a scotch tape can get a copy of my fingerprint left on the reader or the screen. That's like writing down your password on a post-it on your monitor. Anybody dedicated enough can then make a fake finger that can log in.

Not that I'm worried about someone pulling this spy operation on me but if my laptop is lost or stolen, I won't have the peace of mind.