I've had the Executive Field Case (Black/Foliage/Tan) for a few months and I've been thinking about getting a Field Case. I've noticed an oily residue build up on the inside back of the case. I've also noticed the lip on the top left of the case doesn't sit flush with the phone and a little bit of the antenna band is exposed. Has anyone experienced any of these issues with any of their Magpul cases? Other than that, it's a great case for the price.