I had Ghost Armor put on my black iphone 5 but also had plans to get an otterbox defender for it more for the holster. However, after using the defender for a few days compared to using the phone with just the ghost armor on it for a week I took my Defender case off my phone. Overall I didn't like the flaps, size, and the way it got in the way when typing or playing some games on the side. However, when I took my the inner protection of the defender I noticed the plastic part has left some severe indentations into the front protector. It is stupid for the defender to have such hard plastic directly in contact with the screen.
I am going to get my ghost armor reapplied on the front at some point in the next week and not go back to a case. The phone looks too good outside of a case to put something as big as the defender is. So be careful when using the defender with Ghost Armor or probably any screen protector for that matter.