Never used a case, I don't see the point - would you buy a BMW and then cover it in tarpaulin while driving it? 
6 months on and I have a couple of small scratches on the rear, but I've never been that careful with what else is in my pockets. The screen is still perfect.

6 months on and I have a couple of small scratches on the rear, but I've never been that careful with what else is in my pockets. The screen is still perfect.