Well, you guys do what's safe and best for your specific needs, but I learned the hard way about keeping a loaded gun under my bed with a round chambered:
About 8 years ago, I gave my girlfriend keys to my apartment. The first time she used them was about midnight on a weekday, unnanounced. I was fast asleep when she came in, but I woke up becuase something didn't seem right. I grabbed my G23, heart racing and still very groggy/disoriented from being asleep. I didn't hear anything for a while, so I let out a sigh and laid back down. No sooner had my head hit the pillow, my bedroom door swung open and I saw a figure start to move slowly in the door. I shot up, leveled the front sights at this intruder and started taking up the slack and spring pressure. At this point, I was wide awake, with a 55gal. drum of adrenalin pumping through me, every hair standing staight up. I was already commited to the realization I was going to shoot someone that night. This was the real deal. Right as I felt the trigger come to where I knew it was ready to break, I saw a woman's nipple in the moonlight coming from the window and nearly shit a green Twinkie-I jerked the gun away from her so hard it hit the wall.
She thought she was going to "surprise me" by coming over after she got off work. I didn't hear her getting undressed, hence the delay between waking up and her walking in the bedroom. She literally came within a few grams of trigger pull of dying that night and it would have been entirely my fault.
I'd like to think that the time and motion of going through cycling the action would have given me a little more time to think about what I was doing, and a chance for her to have heard me rack the slide.
I've since decided that I'm better off with the chamber empty and the mag loaded, with the gun in the closet shelf, pushed to one side for easy access in the dark. The fear of having a similar event happening again is something I fear more than a true home invader getting the drop on me. I carry with a loaded chamber, but at home it's just not worth it.
Dave