Last night I took a ride all the way from Brooklyn to Montauk Point at the end of Long Island. Great 130 mile ride, that is a combination of city streets, well lit urban highways, and dark rural highways. This is what I discovered.
On the city streets and urban highway, all lights are on - low beam, passing lights and the D3. They are well lit, so I don't need the light, but it is mostly to make myself as noticeable as possible to other traffic. Bright and looks good.
On the dark rural highways, I keep the headlight on, and alternate low/high beam depending on the oncoming traffic. Also, the Denali D3 aux lights are on, as they have a great long throw, and really illuminate the sides of the road that makes it easier to see animals. There were a bunch of deer on the sides of the road yesterday, I was even thinking about pointing the D3s a few degrees to the sides to throw more light on the sides of the road. But I turned the passing lights off!
They create a very bright spot right in front of the bike, and it is very deceiving, which many people do not realize. Human eyes get used to a bright spot that is up close, and can't see far ahead. On the road you want to see as far ahead as possible, to identify potential hazards.
Just sharing this info for others who are considering a set of passing lamps.