I didn't bother with a screen protector on my 5D III, since it's Gorilla Glass.
I was carrying my camera and my tripod head tapped the back of the camera, now there is a tiny (3 mm or so) scuff mark on the screen.
Totally functional, and not THAT big of a deal, but it's definitely not as scratch resistent as I thought.
And I thought "Oh well, I'll just order a replacement cover part", only to find out, it's not replaceable like on the 5D II. You'd have to send it in for an entire new screen.
Oh well. I just ordered a plastic stick on screen protector.
I take good care of my stuff, so this bugs me. Just need to remember I bought it to take images, not to ogle over it's pristine condition.
Still... urgh. Get a stick on protector!
Not!

