All my firearms are secured in the safe, save the bedside .45 (I have children). Bedside .45 leaves the safe when I'm home, goes into the safe when I'm not--will be the same way for the wife (we pick up her .45 today).
I have both a small apartment and two kids' bedrooms to check, so not investigating strange noises is not an option. I'm a very light sleeper. I/We have been woken several times in the night, and usually I quietly wake the wife (if she isn't already awake--those of you that have raised children know how weird sounds NOT made by a child never wake up the wife), and she stands by the phone while I check on the kids. I take the .45 and a flashlight. In the last 6 years, it's never been anything, with the exception of me interrupting my neighbor's 'friends' putting shaving cream and band-aids all over his car (he made a point to come see me the next day, thanking me, and telling me that I scared the bejeezus out of them: I didn't tell him that it had worked both ways).
I don't "secure" the house, but if I hear something, I have to check on the kids. It's just how I'm built. After that, I have to find out what made whatever disturbance that woke me up. The pistol makes me feel safer.