I claim that you work with retards
Will also add that I've had my iPhone 4 for 2 years, have dropped it onto concrete, bricks, tiles, sat on it, had my stupid drunken mate knock it out of my hand and kick it across the bricks (that scratched it), got it wet, you name it.
I also don't use a case.
But, my opinion is just as worthless as yours because personal experiences mean jack shit when there's about 200 million of the things out there.