I have quite a few bikes. The one I'm riding most lately is the one with the dynamo light system working very well.
Here is the article I wrote about it, full with pictures and links to each of the products. Obviously, I'm not going to take them off the bike, so if you want to get together and ride around and do tests, that's a possibility.
Other lights I have:
I have a Fenix pd32 which is super bright but the on/off switch has failed for the second time, and I have to figure out what's up with that.
I have an UltraFire WF-501B which is nice and certainly bright enough, but it eats batteries too quickly.
I have a flashlight from Costco that came in a set of three. It uses three AAA batteries. I don't like AAA batteries, but I gave two of the lights away as gifts, and this is the leftover. I actually like the light, even though it's the weakest of the LED flashlights I have, maybe because I have the lowest expectations of it. It's too big in diameter for me to use standard bike flashlight mounts, though.
My wife has a NiteRider MyNewt 150 or something like that. Very impressive. When I ride in front of her, I keep thinking there's a motorcycle behind me.
But now I'm totally sold on dyno lights.
I just put
this B&M dyno-powered light on my Raleigh Twenty. 40 Lux doesn't sound like a lot, but first of all lumens and Lux are not the same. Second of all, these European-engineered lights do so much work with the optics that you need a lot less light energy to get the right amount of light in the right places.
I can't use your head alone, unless you think some of my batteries would work.
Oh, I also have a Blackburn X4. It's out of production, which is a good thing. It was a very disappointing light. Great mounting system, but insufficient light output.
Again, these round-beam lights seem misguided.