I use two on mine at all times i have a Zag on the screen at all times and then my three cases all have an additional built into the case. I have no issues ever with touch, and i feel much better knowing there is protection on it at all times.I do not know about you, but I have yet to find a screen protector that will adhere and allow me to use it. All of mine have slid or fallen off or have not let me use the touch screen effectively. Is there a good one out there?
I don't resell my old phones. I pass them to my sister after 2 years.Live life. Forget screen protectors. Let your fingers actually feel what it was meant to feel, the glass. Let your eyes see what it was actually meant to see without any hindrance.
I mean come on, why do we protect our phones so much, just so that the next owner can enjoy it? Enjoy it for yourself.
The resale value difference between a cased up phone and a naked one isn't much at all. If anything you're losing more on the cased up phone cause you spent money on protection. Just enjoy life. Being anal just shaves minutes away from your life. Live free.