I haven't read all this thread because of the bickering.
I agree with most of what Costa wrote. Most people that own a 12 ga shotgun can't handle it effectively and are better off with a handgun. I love shotguns. They have a place. For me though if someone has actually made it inside my house the first thing I'm grabbing is my Glock 23C and handheld Surefire Backup. I'll start from the bedroom and my house isn't that big. I know how precise I am with it and can't envision a situation where 13 rounds of .40 cal won't solve whatever problem is present. If it doesn't my AR is right by the bed so I'll just retreat back to the bedroom. Either way light is as important as any weapon. More important than night sights although I've finally found some I'm happy with. 24/7 Big Dot. After carrying my 23C with this site I'm not in the process of changing all my Glocks over to it. If you are an older shooter having problems focusing on the front site like you used to do I really recommend you try them out. I was skeptical about the accuracy of them at first but find I'm actually shooting more accurate than I was before with my Trijicon sights or Defoor.