I;ve put one in my D3 last night and it lasted 2 second, but that was my fault due to human error. I've mis align the protector by a little bit so I tried to peer it off and re-align but end up shuttering the protector glass. Thank god the D3 LCD screen is not damage or scratch.
I think I will leave it without one. After reading the debate over to put one on or not, it seems the pro body like D3, D4 etc LCD is already tough enough to withstand any pressure or damage. I guess thats probably why Nikon didn't include one on their pro bodies. I've read a forum somewhere where it mention the LCD glass can be replace easily if is damage or scratch.