Jim Dalrymple, regarding Touch ID:

Unlocking the iPhone 5S was very slick—just rest your finger on the Home button and the phone unlocks immediately. You don’t have to press or move your finger around waiting for it to be recognized—it just worked.

Also, John Gruber:

Touch ID is very slick, very fast. Almost instaneous.

That’s great to hear. But, that’s the way it’s got to be. Considering how many dozens (if not hundreds) of times a day we’re unlocking our iPhone, imagine how frustrating it would become if Touch ID added an extra few seconds to that process.

Jim Dalrymple’s Hands on with the 5s