That camera headlight can also be used as a filler if you need it. Just have to play with the intensity and distance.
Yeah, for most quick renders I post, I often use it. But I move it around a lot, like you would a normal light (not the best solution, but for quick stuff in here, I don't care). Proper lights are definitely better and I should force myself to use them more often. I'll use a light emitting primitive to make shadow edges softer sometimes.
I think the last render I posted was lit with the headlamp. I moved it A LOT, in all three axis, way up, way to the right and into the scene quite a bit. It was just a quick render and the default lights were weak, so I turned it on and moved it around to create better shadows.