+1 on the h51 zebralight. I've seen no issues, at mid settings you get about 12-15 hours real life, and that's fine for night hiking on steep trails. Fantastic light for night hiking, very good adjuster. I have no idea on the clip thingie since I never use it or bring it, it's a headlamp after all. Low setting is fine for camp chores, and doesn't signal your presence to outer space, ie, good for stealth camping.
The settings are not nearly has hard as it sounds, you set the 3 basic levels before, which then retain their defaults, ie, low high/ low low, medium high/medium low, and high high/high low. Then you cycle with the button, it's easy, really. A few uses and you have it. That single button is sealed so you get I believe true waterproof light. Turn it on, click it the number of times, and that's that. Since you will generally use the same settings for most situations, it really is pretty easy.
The fast battery drain derek reported is either because it was on high, which I never use, that's like a spotlight to light up a canyon or something, or a bad battery.
I use rechargeable nimh AA batteries, works great.
This headlamp is a very high quality device, I asked here and followed the advice I got, glad i did. I wouldn't hesitate to hike on cliffside trails for hours with this light, where a fall would mean death.
The problem with aaa x 3 is very simple, they will if I understand things right fall to the lowest charge of the 3, whereas a single AA will use all its charge, each time. Simpler too.
the different types of h51 are confusing, agreed, I think I got the normal natural light version, can't remember. The light spread is just right for night hiking, you see the trail and enough of the trail edges, it's interesting. There's a few threads here on it.
One day I might try modifying the headband like Bob did, but the regular one is fine, it is very solid though.
this is the one to get, that was the conclusion to make matters simple:
h51 neutral white