I trust what ShooterDon said, I mean shooter is right in his name! But seriously, there are a lot of good points in this thread. Where I'm at is to play out the scenarios in your head. If someone breaks in, it's typically at night in the dark while your sleeping. (or the exact opposite, middle of day when the average target is out of the house, & at work). Now of course there are the random crackheads (is this a PC term?) who intrude while chemically altered at any time of day. Let's go with scenario one: middle of the night. You're asleep and get woken up, you're likely groggy, blind, very afraid, and fumbling. When you are in a serious state of fear, your mind shuts down to basic functions (without proper training), so your fingers aren't going to work as well, your mind is busy trying to process the event, and you are now hopped up on adrenaline making it even worse. So if you manage to shoot towards the door (remember its gonna be dark), it shocks you just as much as the intruder, think of a flash grenade, meant to disorient. Did I mention that all you hear now is a loud ringing in your ears! It's great to think you are a bad boy and going to drop the perp in 2 shots or less, but all that fear says different. So, you get the gun out of the lockbox, point and pull the trigger and it jams (or fails to fire, etc) your mind is not thinking re-rack the slide, or pump again it's thinking just pull the trigger harder or a second time. (again this is all average person without training and practice) This is why the military keeps training, over and over especially in times of peace, the brain will do what it's trained to do. Repetition takes the brain out of the equation, then it's pure muscle memory. For this reason a revolver is a better choice solely based on the events that are unfolding. If you hear someone downstairs or another part of the house, you may have more time, still afraid, but a few extra seconds to get your wits about you. Scenario 2: a crackhead, they wont be disoriented by the initial flash the same as a burglar, and very likely wont get discouraged by being hit once or twice with non fatal shots. Now you want something with more knockdown power, like a shotgun (pick your choice of ammo) or a larger pistol. (sorry to the neighbors, or next 5 trailers in the park!!)
The point is, your only going to be as good as your practicing, so go to the range, or woods, or wherever, puts some rounds through it, get comfortable with it, that's the weapon you're gonna want in any scenario.
I'm of the thought that you will keep pulling the trigger until your mind catches up and tells you to stop pulling the trigger...