I am looking into screen protectors for my 4S, and I have narrowed it down to the Zagg invisibleSHIELD. More specifically, it is now between the Original, Hi-Definition, and Smudge-Proof. I am curious as to if anyone has used any of these three screen protectors and if so, what are some thoughts about them? If anyone has any issues or preferences between these three, or any other brand screen protector that is preferred, please comment! Thank you!