I don't see any immediate changes in the look of the screen, nothing changes (or it's so slight as to be unnoticable, and I do have pretty good vision) when looking at a high res picture with the overlay on and cycling back and forth.
But it is doing something, the button backlighting turns off and turns back on, but only when pressing the native button. Or maybe I'm seeing things from staring at my phone for the last 10 minutes like a jeweler setting a diamond or something.
Edit: It is sharper on native, very small text is more defined. Cool.