I can vouch for the Armytek headlamp/task lamp. It throws a punchy wall of light on turbo; instant access to turbo as well as momentary turbo allows you to conserve battery life by using a lower mode 99% of the time.
While the Wiz Pro throws an all-around useful beam I recommend that your backup light throw a tighter beam by using an XP-G2 for further throw with lower battery drain in case you absolutely NEED to see far away for extended periods.
More than enough for the immediate area. Remember, this is not a thrower. It’s intended to throw out a wall of dispersed light, and that it does.
I really cannot understand, as an hiker myself, some of the comments. Anyway, to each its own.
If I were to carry only one light (which I would try to avoid because of a minimum of redundancy for safety reasons) I would carry a floody headlamp.
Choose one depending on batteries you wish to use. And at least bring some spare batteries 
If you use the light only when needed and not at full power all the time, 3 18650s could last you a very long time. In the pitch dark woods, you can use a low mode 99% of the time and see just fine.
I’ve been very happy with my Wizard Pro. The Only two minor complaints I have is that I didn’t get the warmer tiny version. I got the white light which is fine but at the same time I bought the Wizard I also purchased a Spark in warm tint which is just so much nicer on the eyes. I’ve never been a tiny snob but when you have two lights side by side, you will tend to grab the nicer tint one.
The other minor gripe I have is the Pro is the more floody version yet is still not pure flood. The Spark is more floody so I carry that one at work. I use my Wizard at home and if I’m go out in the woods at night. Works great.
My Spark is the SD-6 460nw
http://goinggear.com/spark-sd6-460nw-xm-l-t6-neutral-white-460-lumen-flood-headlamp-7471.html
It is a great work headlamp. Nice neutral tint and lots of flood.
Doesn’t seem to have the battery life of the Wizard or the power but I’ve not done any tests, that is just my impression.
It is a good headlamp and I enjoy it. My first Spark was a ST-6 (spark uses terrible model names)and it would overheat and not work correctly on high. I gave it to a co-worker who only wanted to use it on low/med anyway so he was happy. I almost got a bad impression of Spark because my first light was junk. The SD-6 is a good light but at the same price of the Wizard, I would just go with that.
If you’re taking along a Miller 102 charger and a couple of spare batteries you should take along a Mini usb too.
Mine works great with the Miller charger and has a very long run time on low and bright enough on high esp. in the woods.
Just put it in your pocket or keychain and forget about it.
One flashlight, so it has to always work, 18650 battery for a good amount of energy, have a good low low to save battery and in case you need to save your night vision, uses current regulation for efficiency, has a bit of throw to see what is going on around you and to find the track
Hmm, that comes out on one of my least interesting flashlights: the Nitecore P12 (neutral version) . In a flashoholic point of view it is boring: my Olight S20 is a much smaller single 18650 light, my UF1405mod throws 40 times as far, my Shadow sc300 DD MT-G2 mod puts out 3 times as much light, my 96CRI SSL80 modded sk68 has noticably better colour reproduction. But you can not have it all in one flashlight and this one is pretty good in everything and at least it looks like it is very reliable.
I find zoomies the most versatile for hiking and camping. I usually use them in the flood mode around camp, hang ’em up in tress for good even light over the stove. Don’t like hotspots when walking with lights either, so zoomies suit me well.
Can be zoomed for focused beam of needed, but so far never needed. The ones I use might not be watertight, but they can handle rain and even being dropped into water for a brief moment. I wouldn’t rely on just one though.
Chose only one? That's easy - Moonlight. Clear sky, full moon of course.
(This does put a crimp in what nights you can go hiking though...)
Why just one? And if you loose/damage it??
Why do not you put a small 1xAAA with you?
Of course, a coupple of knives too (Sak/folder plus a straight one)
And don’t forget some pictures for all of us!!! 
Have a nice trip !
2 DOGS,
I plan on carrying a similar usb stick light, for use just as you described — with my miller. I plan on sealing it in clear packing tape to add some amount of water resistance. A backup light that only weighs a few grams seems worth it to me.
I am weary of the durability and water proofness of zoomies. I do like the throw in a lightweight package though.
I would pick a light that had some way of telling me the charge level of my batteries. Nothing like lithium batteries for dying suddenly. Always a good time when you are 50 feet underwater on a night dive. 
Are there significant differences between the pro and non pro versions? I don’t see any.
That is 1.8 pounds = about 800 grams + 1.3 pounds = about 600 grams, and hundreds of dollars. I thought he was going above ground!
People go way over board with this “two is one” business. A redundancy option is a good thing but it need not be of the same specification. For me a headlight is the main light and a single AA torch is the back up. The same goes for knives. A fixed blade is the main knife and a folder is the back up. When you have to carry your kit yourself you soon become sensitive to unnecessary weight.
I rarely use a light while backpacking/camping, but I know that there are nights that you need one, and also times like a tent blowing over on a stormy night, doing repairs on your equipment or your feet when there is little moonlight, or true desperate emergencies such as needing to treat an injury or find dry firewood or some gear in pitch dark, or even having to stay on the trail all night for some reason.
We lose flashlights, especially small ones, and on a solo hike I think two small but high quality lights is worth the weight, because when you are alone, light could be a matter of life and death in some scenarios
For me, my Fenix LD12, and my Fenix HL10 headlamp sound great, although as I got closer to the trip and weight became more and more an issue, I may want to trim that down to the HL10 and my Fenix LDO1.
I assume you carry a bandanna, well a little light like the LD12 or E01, or LD01, can fit perfectly in the knot of your headband, and at the correct headlamp angle.
The model of LD01 that I have is all the light one needs anyway, so it and the HL10 gives me pretty much everything I need
Another great light is the Photon Proton Pro, the option of using the red led might become preferred. Amazon.com
You could also consider the paklite 9volt light as a back up to your primary light (or as your primary). http://www.9voltlight.com/
Another back up light is Amazon.com
I agree.
I also find that insane!
+1 Lithium AA's are lighter than Alkaline. Outside the city in the real darkness a little light goes a long way.