Have you ever tried an H4 100/80w for increased brightness?
I tried them years ago in my Guzzi. Did not "turn the night into day" for me, but that's only my opinion. First, it was one lamp, second, the alternator was tired and I don't know what the output voltage was, and third, my eyes are not the best. As a comparison, my wife can read street signs farther away than I can (yes, my vision is corrected to 20/20) and sees better at night). Remember - this is my opinion, not a scientific experiment.
For me, the color is as important as the 'quantity' (i.e. watt draw by the lamp or lumen output, assuming more watts means more lumens) - and this might be the way my eyes react to light. Other's have said here (maybe Spiderman?) that our eyes are more sensitive to blue light than yellows (warmer colors). Regardless, I prefer my G6 Led Lamps in my ST over the halogens in our cars.
Something else to consider is why go with a high wattage halogen when a lower high lumen output LED uses less power? The color shift to blue is a bonus (though I personally do not like the higher color temp colors e.g. 6000 deg K and above). Too much of a good thing here is NOT divine.
