It sounds like your real issue is not with the Zagg product specifically, but with glass screen protectors in general that do not cover edge to edge, which is the vast majority of current iPhone 6 glass protectors.
That is exactly what I said. "Right in the area that the phone is unprotected." I saw it hit in that spot (upper left). Were you with me? I don't think so. I'm giving my account of the Zagg iPhone protector that I personally have experienced. Thanks for your input though.