As an iPhone 5s user I have to say that the fingerprint sensor works superbly. I didn't set up the fingerprint option until a few days after I received the phone (my first iPhone) and used the standard password system but once I did set it up I came to appreciate the elegance of the solution. Press the home button to wake. Keep the thumb on the button for a second or two and presto it unlocks. Simple, intuitive, and effective. Classic Apple engineering.