Had my N4 for a few hours and put a dent on the metal frame.

[monsieurms]

It's a bit of a catch 22 isn't it.
You use a case and that metal might as well be plastic because you're covering it up anyway.
You don't use a case and even if you baby it there are some things you cannot account for that may damage the phone.

I've had my HTC One for a year and a half which a have a case on.
But I have never dropped it or anything, this whole time I could have been going caseless.
Although Murphey's law says if I hadn't been using a case I probably would have dropped it lol.

Murphy should not be messed with. He is relentless and will get you every time.