A lot of people on these forums fail to distinguish the type of riding they're going to use the light with... as if one light will work for all types of riding.
I stay away from the rechargeable lights because I tour / bikepack and can't be bothered to sit around and wait for batteries to charge.
I also prefer headlamps for their ability to scan, have a narrower, more efficient beam, pick up animal eyes, critters, signage and occasionally shine an oncomming car if they fail to turn off their brights or a car at a cross street or coming out of a parking lot if I'm not sure if they see me.
There are a couple other factors as well. I do a lot of winter night riding as well. For this I prefer lights with a seperate battery pack so I can keep the batteries warm inside my clothes. Likghts like the Fennix HP 20:
http://www.fenixlight.com/viewnproduct.asp?id=76 Other features I look for are an adjustable focus beam clear of artifacts which can be distracting. Some lights have diffuser. These can be great when off the bike... i.e. camping. And of course multiple levels of brightness or a slide dimmer.
I just got back from a tour where this was my primary light.
http://www.nebotools.com/prod_details.php?id=145&cid=26$40 MSRP
3 AAA
220 lumens @ 4 hours
100 lumens @ 8 hours
220 lumen strobe mode @ 72 hours!
Also has a very wide ranging beam adjustment.
Appears to be completely rain proof, though not certified... and I wouldn't drop it in the water.
Tough light... can withstand a lot of abuse.
I mounted it on my headlamp with a re-useable zip tie.
This trip was a tour of the North Country Trail in michigan. About two weeks and 1100 miles. Lots of singletrack and gravel grinding.
What amazes me about this light is the strobe mode. It's so fast and bright. Perfect for urban and suburban road saftey. People will notice you even among the usual glare of competing lights.
But the really amazing thing is how great the strobe mode was for general purpose night riding on singletrack and backroads.
Sure 100 lumen is bright enough on dark backroads and trails, 220 more then enough.
However the strobe is so fast that I find it didn't bother my eyes. Especially since as a headlamp I narrow the beam down.
I road all night using this light for two nights. The second night I used exclusively the stobe mode.
One night I road the entire length of the 100+ mile White Pines Trail from Cadilac to Grand Rapids Michigan. 100 miles or so at night, 140 total miles.
The last night of the trip from Yankee Springs to home just North of Toledo ohio. That was about 80-100 miles at night and 170 total.
I 20+ of singletrack, 10 miles of hiking along the St. Joseph river at 4am in heavy fog, but mostly just a lot of the dirt and gravel roads i love.
Nothing beats the nightlife, the critters, wildlife and deer, riding into the sunrise, watching the world wake up, watching the fog burn off.
It's an incredible experience.
I should also say I recently hunted down and stocked these lights for a local shop. We sold eighteen of them in the first week.
They are a 1st gen bike light from a fairly tried and tested tactical light maker. Indeed eople had been using them for biking before they came out with a bike mountable version. That said there have been some minor issues with the bike mount. The light can be bounced from it. Most people just turn the mount around on the light. It's just held on with two screws. Problem solved. I prefer to just put a re-useable zip tie on it... and most often just skip the mount and zip tie it to my helmet.
