Infraction for not filming your mall ninja-ryEveryone is making very good points.
Personally I have a Glock 21 with a surefire x300 on my night stand, because it's what I'm most comfortable with and I feel the ability to clear corners without running the risk of someone grabbing a barrel is better.
I'm not a professional, I'm not a soldier, I have never been trained in how to clear rooms, but when I did dry runs in my house one day while no one was home I found I moved much easier with a handgun than I did a rifle and for sure more than the shotgun, and since I am more familiar with the handgun, I point it more naturally in the dark when you can't always see your sights.