My L920 fell from a table in a restaurant and landed face down on the floor. To my surprise, there were no scratches on the screen. A few days later, it falls from a machine I drive at work. It doesn't hit the floor, but it dangles from a cord connected to an external battery and hits the side of the machine. Now there is a small scratch on the screen. It's noticeable at the right angle with screen off. I can't feel it with my finger, but I know it's there, mocking me.
I don't want to hide the beauty of my phone, but I've ordered a case and screen protector.