The Real TouchID Long Term Reliability Problem
There are a ton of people that think that TouchID will become flaky over time like the Moto Atrix's sensor. I think that TouchID is a lot better protected than the Atrix's sensor, but we don't know how effective that is going to be.
However, TouchID is on the home button.
The home button on iPhones has for a long time been a reliability issue. TouchID significantly increases the number of times the home button is depressed for people who used to wake their phones with the power button. Which means unless Apple has silently improved the button part of the home button by leaps and bounds, the home button will become unusable very, very quickly.
When the home button becomes flaky, you can no longer easily wake and unlock your phone in one smooth action. The sensor is not power on authenticate, you have to push down the button to wake and leave it on for authenticate. It works nicely, but if you resort to waking your phone from the power button since the home button has become flaky, the elegance of TouchID wake and unlock will be lost.
Homebuttongate anyone? Or do you think that the button mechanism on the 5S is a huge leap forward over previous iPhones for some reason?