I will say that I much prefer having a weapon mounted light over a handheld (for primary light). Though, as noted it's a useful skill to learn. To that end, even with my weapon light I still have numerous flashlights staged all over the house; my wife says I have a problem
. Anyhow, the reason I mention preferring it that way is that because of a class I took about a decade back. As part of the class we went through a brief lesson inside a shoot-house and were individually allowed to run a course of fire in there. Trying to do things such as open doors, and "cutting-the-pie" (clearing corners) were very difficult with both hands occupied. That was my first revelation.
The second came once we started having kids. It was discussed that in a home invasion scenario, the best course of action is to hunker down and make the perps come to you. Funnel them through a doorway where you have the advantage. Except in the case where you're trying to get to a loved one's room. In that case, you're likely to need a hand free to handle kids while also manipulating your firearm. Again, difficult to do with a flashlight in one hand and gun in the other.
So, I say all that to note that it very much depends on your situation. Me, I'm using my weapon light as primary. Also, I should point out that the argument that you'll have to point your gun at anything you want to identify isn't as one sided as it would seem. Most weapons lights are powerful enough now that the spill over from the beam is significant. Of the lights I own for pistols, several Streetlight TLR-1 HLs and a Surefire x300, they all provide more than enough output that I can point the gun toward the ceiling and still easily identify an object across my living room ~40 ft away. Once identified, then you can decide whether to train your gun on the source of the noise.
I'll end with the fact that I'm really excited about the new Streetlight TLR-7. Can't wait to pick one up.
Oh, and for anyone that thinks I'm dissing the use of a handheld light, here is my collection of flashlights that just reside in the master closet. This doesn't even count the numerous one's scatted throughout the house. I mean, one is none and two is one right?
