So Far
Apple is not being hurt by this: backing a two-ton car over the sapphire glass shatters it. Well, the rest of the phone is crushed too. Something's gonna bend if a Corolla runs it over.
It will have some failure points. But the tests it passes are the ones you really want to see. No scratching that makes the phone hard to use. Ugly. I wonder how it does with finger-grease?
I must have dropped my iPhone 5 25 times or so, no breaks.
A friend of mine forgot he had his iPad mini in his back pocket when he was getting into the car. Glass and camera not working. The Genius, out of warranty, sold my friend a whole refurb of a 64 GB mini that sold for about $700, for $219. Not bad. That would have broken no matter what material the glass was made of.