wtc911, please feel free to disagree if I am incorrect.
Veni, knowing your home is key. You have figured this out. In your situation I agree. If possible keep the light low as you know where your furniture is and they don't.
I have a 3000 sqft home with the kids upstairs and the our bedroom down. I don't have your option. It is different for everyone, and everyone needs to really think about their situation. You have and you are asking questions. Good job!
My wife has one job when something goes "bump" in the night...kill the lights.
My house has three levels. Family bedrooms are on two of them. I can't afford to sit in bed and dial 911 with daughters sleeping downstairs, if i sense a threat I have to investigate. However, 911 will be called by the wife and if there were no others in the house then the right course of action (if you are certain of an intrusion) is to sit tight, be armed and ready, and call the cops.