I used to be flash on all lights all the time and hopefully someones eyes would sear.
Now I use a steady light on my rack and a pulse light on my helmet. This all seems to be more than enough for drivers and I have yet to have anyone yell at me to turn down that light. I have has this happen in the past with a ton of pbsf lights, a drive yelled at me because he could not see.
I have also decided that I do not need a 1000 lumens coming from the front of my bike anymore. I have a 550 lumen light but keep it on low and a 120 lumen light that is on high.