I enjoy watching the videos that are prepared by NRA and Rob Pincus' outfit, and I have purchased many over the last year or so. One of the comments that stuck with me that Rob brought up was the fact that when folks went through training with their back up pistols and short barreled ultra 1911's few got through the training without mechanical problems. In fact many of the weapons could not be used to finish the course. So his point was that its better to carry a full size or close to full size pistol if you are expecting 100% reliability with your defensive weapon. This training was geared more for the police officers than just concealed carry users. Most of the small hideout or ultra size weapons work for defensive use but if you get into a serious exchange of rounds the possibility of a jam or misfire goes up with time and use. The majority of us who carry for defensive purposes will never have an issue since defensive exchanges are usually over in seconds. So the compromise carry of a small light weapon works just fine. If you want the security of knowing you can clear the mall you best pack a full size weapon and have extra magazines.