I had my phone on a window ledge, below which are a couple of towel racks. I grabbed the phone badly and it dropped, and in trying to retrieve it before it hit the floor I ended up pushing it up against the end of the towel rack where it slid down a couple of inches before I could grab hold of it.
The Zagg has a few light scratches on it that I can see with the phone off and holding it against the light just right. I can also feel them with my bare finger. I guarantee a film protector wouldn't have fared so well. I don't know about the bare screen, but it seems to me at the least it would have gotten the same scratches--and maybe even with the film protector in front of it.
Anyway, this Zagg has a lifetime guarantee. At some point I will replace it, should I do something similarly dumb and cause more damage to it.
But at least it kept the screen itself from damage, which is well worth it should I choose to trade the phone in.