It's been nearly 15 years since I returned from my mission, but I still leave it as a one-line blurb in the personal section of the CV. Potential employers look in depth enough at my profile to wonder about the two year gap, but more importantly, I think it's overall a minor asset for the reasons that you mentioned. Keep in mind most jobs I apply to are overseas, far from the heart of CougarBoard, and I've still found that to be the case most of the time. Furthermore, I'm a little confused why you'd feel guilty about using your own personal experience as an "extra benefit."