I was never a fan of headlamps for night running. The shadows are minimal given the proximity of the light to your eyes. Instead, I prefer a handheld flashlight. My all-time favorite- the Fenix L2D. It's blindingly awesome!
I have a Gomotion Trail Runner Vest. It's been my companion for dark runs for the last 8 months, and it has proved itself. I like that the light is mounted at my chest, lighting the space directly in font of me. The light swivels up or down, and the beam can be focused in or out. A blinking red light is found on the back of the pack, a pack that holds a 1 liter hydration bladder easily. THe pack fits snuggly to my back, and I have had no issues with chaffing or discomfort. I would give it an 8 out of 10.
For trail running in the dark I go with a two-light setup, one on my head and one on my waist. I like a lot of light because I've kicked a stump wearing Vibrams before dawn in an ultra and saw through time. I like to have my hands free for my water bottles too.
My headlamp is a Petzl Myo. Great light. On my waist is whatever good-but-not-too-expensive light I see fit to wear. This also has the advantage of always having the trail illuminated in the direction I'm going, but also letting me see wherever I am looking. When I'm looking forward, the two lights really cut down on shadow problems.
I tried the light-on-the-waist and chest ideas, but wasn't happy with the light's throw. I think I'm in the minority with the preference for the handheld.
Good topic, I have a 24-Hour ultra in a couple of weeks and have been thinking about this. Last year we carried flashlights. My husband tripped on a root and just about body slammed me into the dirt. I was thinking of one of those hunting/ball cap styles with the little LED lights in the brim. Not sure how good that would be though. Hubby redneck cousin had one on and it looked pretty handy.
And I was called nuts in "that other forum" for wrapping head lamps to my ankles in the thread "How to make a buck off of nothing on your feet" or something like that. It was acutally a joke knowing that they would bounce around too much to actually help light up the path. I did try them out first after all, so I should know. ;-)