For the past few years though, for the other 10 months of the year when I was running in the pre dawn darkness, I would stick to my routes around town under the streetlights. I had a low powered LED Hdlp that I had tried for running on trails, and while it was fine around a campsite, it wasn't nearly bright enough for running. Last year I got a higher powered headlamp, and it changed my running. Rather than having to contain my trail running to weekends and weekday mornings during the summer, I was able to hit the trails any time I wanted, and had no problems with lighting up the path in front of me.
A few weeks ago I got my hands on a Coast HL27 Headlamp (http://www.coastportland.com/hl27-focusing-led-headlamp.htm).
The brightness on this headlamp is good. The website says it puts out 309 lumens, and when you have it focused (more about that in a moment) the beam reaches 122m. To put that in perspective, if you're running down a trail and you look around, it will easily reach all the tree tops and light up the eyes of all the creatures around that are watching you (I tend to keep my eyes down when running trails in the dark just so I don't see all the eyes and freak out).
About the focusing- this lamp has a focusing feature. You can twist the bezel to change the beam from a concentrated hot spot to a wide spread, which is more useful for general purpose usage, like if you were using it around a campsite. For running on trails I tend to dial it back just a bit off the most focused, so it gives a little bit more spread but still has a bright hot spot.
It also has a dimming feature, which is nice. Most LED headlamps have a bright and a dim feature, but this has a dial you can turn to adjust to whatever brightness you want. When running on trails I want all the light I can get, but when I come back out on the the roads I turn it way down, which will greatly improve the battery life, and also still gives me some visibility to cars. The other nice thing about the dimming feature is that it makes it a bit better for general usage than other high powered headlamps, For example, even on the dim setting my Cree headlamp is too bright for reading- it's blinding on the white pages of a book. This headlamp can be adjusted to whatever brightness I want.
This headlamp uses 3 AA batteries, and has an published battery life of 3.75 hours on the brightest setting. I'll take their word on that- if I'm going to be running on trails with this headlamp, I'm not going to let it drain the batteries right down so I'm running with no light.
For price, this is a pretty good deal. You can get it on Amazon for about $50. As a comparison, if you buy a higher end Petzl or Black Diamond LED headlamp you'd be starting at over $100, and can go way up from there.
All things considered, I'm happy with this headlamp, and I will continue to use it for running. I have a race coming up this weekend that starts at 5am, so the first 1.5 hours will be in the dark, and I plan on using this lamp. I think that says enough.