No... I am not talking about my mental faculty -- though there are times that that argument could be made -- I'm talking about fog.
Last night, it was foggy. Very, very foggy. This made riding a little interesting and drove home my contention that there is more to a light than sheer brightness. You see, I was running DiNotte's 5W light on my bars -- I wanted to get re-acquainted with the light -- and Nite Rider's MiNewt on my helmet -- not a bad combo, to be honest. However, thick fog negated my use of the helmet light completely -- a note to anyone who says that a helmet light is all you need, in fog and dust all you see is the light reflected back to your eyes -- and with the 5W on high beam I could barely make out the gravel road ahead of me. T. was using DiNotte's 3W and he was having trouble with it on low.
My point? HID's cannot be dimmed far enough. With a HID I would have been essentially riding blind, only able to see the brightly illuminated fog through which I was riding. LEDs are supremely dimmable, and this not only helps out in foggy conditions, but also allows you to stretch your battery life by reducing the output when it is not needed, like climbing.
Let's use the Lupine Wilma as an example. On full power, it'll bleed it's battery dry in 4 hours -- 3 hours is claimed, but I measured more than that. On low, however, it'll last 33 hours! And this is from a small Li-Ion battery. Near HID brightness -- 420 lumens -- but the light level can lowered when needed or desired. And though I used the Wilma as an example, I could have used the Big DiNotte, or BR Lights, or numerous others to make my point.
The next feature that sets LEDs apart is a blinking mode. These high power lights make for high power flashers, too. Again using fog as the antagonist, during daylight hours I have found myself commuting in a fog bank. Now, I don't want to get hit, cut off, narrowly missed or any other mishap that could happen should a driver be unaware of my location. Put one of these super bright lights on flashing mode, and it'll be seen at high noon in the desert. Princeton Tec has the best flashing mode, but most of the others blink on and off as well. Anything that makes dicing it up with traffic a little safer is a good thing in my book.
Now, if ultimate brightness is your thing -- you know who you are -- then you can't beat a good HID... yet. Take a look at Light and Motion and Lupine (if you have a fat wallet). Or, you can wait a little while for the next crop of emitters to hit the scene. Either way, you'll end up well lit.