My friend installed a hard casing few days ago on his iPhone5, just now he took it out to clean the dust on the screen and install screen protector, then only notice there are scratches all over the bezel!!!! 

does this happen to you? luckily I bought capdase soft jacket, so cant experiment issue like this

But there maybe come another prob, when u take out the sticker, the paint may peeled out together with the sticker, since it is so sensitive...

the built quality for iphone 5 is superb. it is not meant for you to use casing on it. it is for you to carry it nakedly to feel the aluminium texture and the slimness of the phone. putting casing on defy the purpose of Apple in reducing the size and weight. if you use it with care, there's no need of any casing for protection. i use mine naked, even if it get scratches, well, is there a phone out there that won't scratch after usage? don get over reacted.
just my 2 cents.