Are you looking for a light to see or a light to be seen? To be seen, I use CatEyes and run them in blink mode whenever I ride in marginal lighting, shadows, or in town. Remember, most bike and car collisions occur when the car pulls in front or turns in front of the bike, so the front blinky is more important than the rear blinky. I don’t ride in the dark, but the commuters seem to favor Dinottes and Magicshines.