I'm been thinking about trying out IDPA. My CCW of choice is my trusty XD .40 Tactical and will definitely be my IDPA gun of choice. I have a solid stainless guide rod, recoil pad, extended slide release and extended mag release. After looking at the IDPA rules book it seems that the extended mag release is a problem. Why? I could understand if it was in the SSP category but an extended mag release doesn't seem like that radical a modification for ESP. Could someone explain the reasoning on this?