Taliv has a point. A long time ago, I would have argued the point about how much better a pistol was at home defense. Then I saw an article by Clint Smith in which he demonstrated that a carbine isn't any longer than a pistol is when held at arms length. I tried it, and sure enough, my assumption was wrong. To be fair, I had never done much work with a carbine, though I did do MOUT training with an A3 so I knew a few tricks. In any event, the AR that sits about 10 feet from me right now is loaded and ready to go if I need it, and that is a comfort.
Nothing wrong with having wrong assumptions if your willing to admit when you're wrong and are open minded enough to reconsider your views and try new ideas if you don't have much experience.