I have been mounting two Schmidt E6 halogen lights on a Minoura Swing Grip attached to my stem. This has, until yesterday, worked wonderfully. The lights are lower than the handlebar, which helps bring out texture of the road surface and helps spot any debris or potholes. And, the lights are easily accessible. This is great when climbing steep hills so I can turn off the secondary light.
However, there's always a catch. Yesterday, during the second half of the "Arduous Arbuckles" 200 miles permanent, the T-bar on the Space Grip broke. It was a clean, fatigue break caused, no doubt, by nearly 8000 miles of riding in this configuration. Fortunately, the bar didn't completely separate from the center section as it was sort of held by the light wiring strapped to the center section. But, something had to be done before nightfall to keep the lights from flopping around.
My rando solution was to use a length of duct tape (you do carry duct tape, right?) to bandaid the assembly together. Fortunately, the tape did the trick and I was able to use the lights for the 53 miles from the last control to the finish.
I guess I'm back to mounting the lights on the forks using stubs.