noglider 

That sounds like a good analogy. I had a high power flashlight with a round beam, and I thought it was fantastic. But the mounting and charging were cumbersome, and I noticed that my eyes gravitate to the hot spot in the center when I really should have been focusing on the far edge of the beam. Not only that, the brighter the light, the harder it was to see outside the beam. So I lean towards dim lights. They do limit my speed, but that's OK with me. My main commuting light is either a B&M Ixon Core rated at 50 lux or a B&M something-or-other dynamo headlight, probably with a similar rating. They might be around 200 lumens. That sounds woefully inadequate to some, so to each his own. With car and motorcycle motors, there is an axiom that says once you increase power, you never go back to lower power. That doesn't seem to be true with me. I can adjust. I'm sure if I rode off-road, I would want a powerfuller light.