The headlamp is kind of ugly looking compared to the refined designs of more expensive lights, but it is functional.  The primary issue I have with this light is the plastic mounting bracket that holds the light assembly.  There are two plastic clips that snap around the battery compartment and allow the light to swivel up and down, sort of.  These clips don’t seem very durable and I’m always afraid they will break when I remove or re-attach the light.  Luckily, there is only one reason to actually remove the light, and you only need to do it a couple of times when you first get the headlamp. (Edit: one of the clips broke while taking pictures for this review)

The main issue with the clips is that they don’t stick out far enough, which causes the back edge of the light assembly to hit the base plate when turned to certain angles.  This is an obvious design flaw, and I’m really surprised the headlamp went into production like this.  However, I was able to use a Dremel to grind away part of the base plate and allow the light to turn more freely.   This is a required modification in my opinion, so plan on taking some time to do this if you purchase one.

The runtime on a single AA Energizer Lithium Max battery is almost 7 hrs on medium.  That is great for a single AA cell, but will not get you through an entire night.  The ease of replacing the single battery helps mitigate that annoyance, though.  I have replaced the battery in the dead of night without taking the headlamp off of my head, or using a second light source.  You just unscrew the cap, let the old battery fall out, insert a new one with the positive nub sticking out, and replace the cap.  Very quick, and very easy.

The runtime on high is not so good, only a couple of hours at most.  The difference between medium and high is not that great during real use, so the extra output is not enough to justify the increased battery drain.

The low mode is only bright enough for easy hiking and reading, in my opinion.  I almost never use low mode during a race.

The headband is not quite as comfortable as the Petzl Myo XP that it replaced. The plastic base plate doesn’t seem to conform to my forehead as nicely, and can become very slightly irritating after wearing it for a full night.

The Fenix HL20 does not come with a top strap, but has a place to attach one. I prefer using a top strap, because it allows me to wear the headband more loosely and still feel that the headlamp is secure. I removed the old strap from my Petzl, and it has worked just fine on the Fenix.

The diffuser lens attaches more securely than it appears in the stock photos.  There is a small “fin” of plastic on the inside of the clip that fits into a groove around the light and prevents it from slipping forward, and off the lamp.  From just looking at the product photos,  I was afraid it might fall off during bushwhacks.  It has proven to be a non-issue though.  I never worry about it falling off.  (Edit: this also broke while removing for a photo!)

The lens does an adequate job of diffusing the light, but is far inferior to the Petzl.  The design can cause a glare from the bottom of the plastic lens, which is distracting.  I suggest using some black paint around the bottom edge of the flip-down lens to subdue it.  A black sharpie will also help a little bit, if you don’t have paint.

When storing this headlamp in a pack, you should partially unscrew the battery cover to prevent the light from being turned on.  The switch is not protected, and it is very likely you will have a dead battery if you don’t take this precaution.  The cover can be unscrewed enough to prevent the light from turning on, but not fall off, and the o-ring will still keep it sealed from the elements.

After 6 to 8 months of use, I started having problems with battery life.  Instead of 7 hours, I was only getting a little over three.  This is the runtime I would expect if running the lamp on high, but I was using medium.  I’m not sure what happened, but battery life is consistently bad these days.  I think the warranty would probably cover it, but I couldn’t find a U.S. warranty address, or my receipt.  At $40, it seems easier to replace than to warranty.

The light still works fine, but the reduced battery life makes it inconvenient for racing.  I’m not sure if I will get another, or try a different light.  If not for the runtime issues I encountered, this would be a great low-cost and light-weight light for AR.

Pros

• More than 7 hours runtime, on medium, with a single AA Energizer Lithium Max battery.
• Lightweight (75 grams with diffuser and top strap, no battery).
• Cheap.
• Nice, relatively smooth beam with good throw for its size (like other Cree XP-E R2 lights I’ve seen).
• Very easy to change the battery, even in the dark.

Cons

• Angle adjustment is poorly designed and has a minor defect, requires modification of the mount to work properly.
• Not enough runtime to last all night at medium level.  One battery change will be required.
• Diffuser lens is adequate, but also requires modification to reduce glare.
• Too easy to accidentally turn on the light when stuffed into a pack. Pulling it out and finding a dead battery is likely, unless you partially unscrew the battery cap to keep it off.
• Plastic pieces are easy to break when removing for review photos.  It’s best to put these pieces together and leave them alone!
• Possible reliability issues with the LED driver?  No U.S. warranty location?

Neutral observations

• Very utilitarian design.  Not as refined looking as a Petzl, Princeton Tec, etc.
• The headband is not assembled or attached when you take it out of the package.  I had no problems threading it, but can imagine some people might not get it right on the first try.
• Mount has an option for a top strap, but none is provided.  It is lightweight enough to do without, but I added one and prefer it that way.

If you’re looking for a small, basic GPS at a low price, then the Garmin Foretrex 101 may deserve a slightly better rating than I gave it. Although I didn’t buy it for athletic training purposes I was hoping that it might serve a dual purpose. If you primarily run in a straight line in open areas or along roads then it works pretty good for recording distance ran or biked. However, here in the hills of western North Carolina the cumulative distance counter was significantly off the mark on almost all outings.

My testing was done on mountain trails with roughly 1500ft of elevation gain/loss and under tree cover, though all of the leaves had fallen and the only thing blocking a signal would have been the bare tree limbs. I don’t know how often this unit records position for determining distance traveled, but I can only guess that it is missing the many turns encountered on an average singletrack trail. I ran and biked the same trail and recorded a distance of 6.75 miles with the Foretrex, while my bike computer (recently calibrated) showed nearly 8 miles. Additionally, based on my usual training pace, the 8 mile result seems more accurate. That makes the Foretrex result almost 20% low! While biking along relatively straight forest service roads, the difference was closer to 10%. One thought is that maybe it is not computing the added distance created due to elevation gain and loss? I’m not sure, but the discrepancy is too much for me to consider using it as a training device.

When used strictly for determining coords while standing still, I can’t find any faults with this unit. The only negative thing I can say is that I’ve never seen any benefit to the WAAS mode. It is supposed to allow much greater accuracy, but it has never worked during my testing. I guess I’ve just never gotten the signal for the WAAS in the areas I’ve used it.

Although it is designed to be worn on your wrist, I found it to be uncomfortable at best. When bushwhacking through the forest it became very painful when I had to put my hand down to brace myself. The unit extends beyond the wrist and digs into the back of your hand when your wrist is bent back. The additional elastic strap for wearing on the upper arm was much better. The bike mount is very secure and seems bombproof.

The 101 model uses two AAA batteries, which allows easy field replacement. Rechargeable AAA’s seem to give me about 4-5 hrs of continuous use.

My primary use for this gadget has been navigation training and confirming CP placements for training/mock races. It works just fine for these purposes, but not much more.