I had a great conversation with a motorist the other night. I had the Dinotte taillight on, pointing straight back and i was riding in the pissing rain at night. A car passed in the far left lane then pulled back in beside me at the stoplight. rolled down the window and thanked me for having such a bright light. He said his biggest beef with cyclists is half the time you cannot see them , even with the tiny blinky lights. Driver said my light was very bright, and he was able to spot me right away, from over three blocks away, giving him ample time to pass safely.
I had have transport truck drivers thank me too, the light is visible from high up in the truck cab, unlike the smaller blinky lights. As a truck driver myself (albiet a lightly smaller 5 ton) i can relate. I notice that when i'm biking on the freeway (we're allowed to here) trucks change lanes when passing me, then change back into the right lane once they've passed.