Far and away, the most compelling upgrade worthy feature on the new iPhone 5s is the new Touch ID fingerprint sensor. It was a feature that was rumored for many months, and today the general public can finally see what all of the fuss is about.
I've been putting the Touch ID sensor, which rests inside of the iPhone 5s' redesigned Home button, through its paces all morning. I've come away extremely impressed — not only with its ease of setup, but with its uncompromising accuracy.
After using it for a while, it's readily apparent that this is not something that Apple hastily put into the iPhone 5s. This isn't your father's fingerprint sensor. Touch ID is a feature that Apple has meticulously meshed into the iPhone to make one transparent and cohesive experience. And it just works.