lawrence, i am admittedly a little late to the party - however, your post promoted me to add my experiences re: scratches because i have no idea how your got your confidence. in my experience, it does not take a whole lot of abuse to scratch up the precious screens. it has happened to both my iphones - 4 & 5 - especially the latter... when i upgraded from 4 to 5, i actually thought that the problem was solved as i, too, had heard that the 'new' glass would be practically 'un-scratch-able'.
well... not mine. all it took was wearing the phone in the back pocket of my jeans and placing it inside the inner pockets of my purses for the glass of my iphone 5 to end up looking like i had tried out diamonds on it...
to be more precise: the glass ended up showing distinct scratches mainly on the right side of the screen. i am still puzzled what could have caused this as it would have had to be a repeated motion.
i only noticed this after weeks of using it unprotected and only by chance, namely when i placed the phone under a lamp that hit the surface just the right way. wow... the only thing i am guessing is that the glass had come in contact with the car keys inside my purses. this, however, does not explain why just the right side ended up so... worn.
i generally handle my possessions with care and was stunned when i saw what had happened. in any event: i was lucky to have the phone replaced due to a software problem (longer story) but the first thing i did when the replacement arrived was to cover it with a screen protection.
since i have tried different types over the years, i, too, love the glass versions. as everybody else, i am waiting for the perfect fit for my 6+. both are yet to arrive... ;-))