I guess I'm lucky in that on a 10 mile commute, I am rarely facing oncoming traffic, either bike or car. Also, since I'm in NYC, I don't need lights to see except in a few very short stretches. So many of our streets are one-way.

My lights are a Lezyne Super Drive, about 450 lumens, and a Keygos flashlight, about 5-600 lumens. They are bright and the biggest problem on my commute, day or night, is pedestrians in the bike lane. These lights make them plenty aware that I'm coming, and I don't use them together.