Going up the Main Trail this morning (Fri 10/21) it was dark until the Switchbacks were reached. From the creek crossing at the Mirror Lake outlet until Trail Camp, I used both a headlamp and a flashlight. The combo seems to help me navigate this area more safely. Turns, sketchy areas, bid drop offs/ Big Air in the distance seem to be better and more readily defined, as well as the area a few yards ahead. I never see any other hiker using a flashlight, so maybe I am just wasting batteries and adding weight. (Also, if one fails or is lost, I still have the other to use.)
Of course, it is probably best to avoid hiking in the dark on much of the trail. Unfortunately, I am too slow to start and finish in daylight this time of year. Seems best to do the night part first when fresh, rather than at the end when tired.