The wife and I keep them with full mags, none in the chamber, uncocked and safety off. They stay in the safe but the safe is unlocked when we are home (the safe is in our bedroom).
We keep them like this for the racking sound, to give the bad guy an early warning that he has significant oposition, he/ they will hear this sound from 2 different parts of the house. My semi auto makes a large racking sound when chambering the first round, we all know what the wifes mossburg 500 sounds like.
I have read the oposition to this way of thinking ie: gives away your position, but I don't really ever want to kill anyone and will take my chances on them fearing the sound and fleeing before pulling the trigger.