I got the iQase FILM while I was waiting for a case I liked, or deciding if I wanted to attempt something more complicated like the invisibleSHIELD or bestscreenever full body protectors that use solvents and come in several pieces.
I'm still not sure I want one of those, the photos make them appear to be fairly visible, so I'm waiting to see if someone else tries it where i can hold one and see for myself.
I am happy with the iQase, installation was as easy as lining up one edge and dropping it, I can't really feel any difference from using it before I put it on (it's not sticky or rough), and I can't see it once it's installed... they only way to tell there's a film on it at all is to turn it off so the screen is black, hold it in bright light, and look for the edge of the film where the home key and ear speakers are cut out. You can't really see the outer perimeter edges since it is cut to line up to the edges where the glass meets the sliver trim.
It also comes off easily, just stick some tape to it and pull, and I haven't noticed any wear or edge pealing in a week of it being used in and out of a pocket with just the film on.