Love pistol caliber carbines. I shoot indoors and 5.56 is just no fun. I have an UZI carbine that I finally got around to making a SBR. Wish I wouldn't have waited so long, it's super cool. Small, robust, reliable,cheap magazines and super easy to hit with. You guys that can share magazines between carbine and pistol have it even better. I definitely think pistol caliber carbines have a place for defense in the home or in an urban environment. The 9mm picks up some juice running out of a longer barrel and it's easier to shoot without hearing protection if you must do so.