This will be my first time using the NEXT trade-in program. I'm looking to preorder then mail in my phone to Apple once I receive the new device. My current device still works 100% but there are definitely scratches on the screen (no cracks), and some dings here and there on the outer casing. I showed it to an AT&T rep a few weeks ago when I went in for a billing question and he thought it was fine, but I'm wondering if anyone's had issues with trade in quality in the past? Is it mainly only an issue if the phone is not functional or the screen is visibly cracked? Thanks!