I have sveral Surefire 6Ps sprinkled throughout the house. One in each car, and one one the motorcycle.
The only time the M&P gets a mounted X200 light is when I go to bed. I don't like having to point my gun at someone unless I'm ready to shoot them.
Otherwise I also carry a 6P on my belt when going outside at night.
Also, look into getting a cree upgrade, as it siginificantly increases the brightness of your surefire.
I also picked up this bad boy last week, and it is BRIGHT:
I bought the recharger and rechargeable batteries to go with it.
In my mind, a dependable tactical flashlight is neccessary equipment inlow light situations.