I used a Dinotte 200L with the 2-cell, and later the 4-cell, battery for two years or so. Yes, it is an amazing light, and well constructed, but that said, after a year or so the wire started pulling out of the battery. No crashes, no violent events, just living in my bag or on my bike. Dinotte was decent, but not great, about replacing the battery even though it was under warranty: they gave me half the replacement cost.

Getting the new battery did fix the intermittent connection problem that I had.

I recently got all my good lights stolen and decided to not replace with Dinotte. The reason is simply that I wanted something brighter than the 200L, but not their 800 model, and their 400 model requires a screwdriver to attach and remove from the handlebars. Yuck. So I went with a Cygolite Mitycross 320 which has been a great light thus far.

The best setup I've found thus far is this: your biggest, brightest light on the handlebars along with a blinkie, and a bright, not insane but bigger than a blinkie, light on the helmet. Before that consisted of the Dinotte 200L on the bars and a Sigma Karma Pro on the helmet, both around 200 lumens. After having all that stolen I'm now using the Cygolite Mitycross 320 on the bars and a Niterider MiNewt Cordless 150 on the helmet. Having a bright light you can throw around with your head makes a HUGE difference both for seeing around corners and for cars seeing you. I was amazed at the difference when I first got my helmet light. That said, you want your better light on the bars for the reasons stated above: shadow relief and whatnot.

When considering a helmet light do think about how easy it is to remove. The Sigma Karma Pro was pretty much permanently attached (zipties) which meant that even when riding during the day I had half a pound of light strapped to my head. Even if you can't remove the mount itself, just being able to take off the light is good for both comfort and security (I really hate hauling my helmet around with me).

At this point I think that the "Dinotte or 'nuffin" approach is anachronistic. Two, even three years ago, yes, Dinotte was head and shoulders above the rest. My first light was the Niterider Sol which died after riding in the rain for two or three days. My second was the Cygolite Dualcross (200, I think), which was a great light but frickin' huge. Now, however, Niterider and Cygolite both offer products beyond anything Dinotte has (self-contained 100 - 250 lumen lights with decent battery life), and most of the well known brands have figured out how to make good connectors that are water tight and reliable. I'd never heard of or considered a Sigma light, but the Karma Pro went through an entire Seattle winter, on my helmet, with nary a hiccup. I didn't really consider Cygolite as a replacement for the 200L until I realized just how small their lights and batteries had gotten: the Mitycross is about the size of the 200L, has a better beam pattern, is brighter, and only sacrifices half an hour of battery life (compared to the 2-cell battery). I think Dinotte has been sitting on their haunches while the other guys are catching up, or in some cases, passing them.