Ledlenser MH10 Rechargeable Headlamp LED

This headlamp is not for ultra or trail runners! First off, this claim of 600 lumens at 10hrs is simply not true. When running with this I had it on the high 600 lumen setting but within 1-2 minutes it automatically drops down to a noticeably lower lumen output. There is no way to keep it on at just 600 lumens. I literally had to turn the lamp off and then back on again about 50 times on a 10 mile night run to get back to the brighter 600 lumen setting...again just for 1-2 minutes before it dropped down again and repeat the cycle. I also did a test of battery longevity. Fully charged, I turned it on at it's highest 600 lumen setting and let it run until the battery died. Keeping in mind what I mentioned above that after 1-2 minutes it drops down in lumens, I only got just under 8.5 hrs of battery run time. Considering that this wasn't at 600 lumens, save for the 1-2 minutes when I first began the test, that is well under their claim of 10 hrs run time at 600 lumens. That's the biggest disappointment but there are many other things that I do not like about this lamp...again, as a runner. The lamp is very backside heavy because of the clunky battery pack and it does bounce some. The bezel that spins between flood and spotlight didn't work well. I really had to work it just right to even turn it. Because the lamp itself is just one piece the spotlight feature is pretty worthless, very tight narrow beam, no runner would use this setting. The flood light is ok, but again, after it automatically drops in lumens after that first 1-2 minutes, it too isn't very useful. These should be two separate light pieces, one flood and one spot to compliment each other and be more effective. The headband, I have a fairly large sized head and I had the slider as tight as it would go...which for me was just enough but a smaller head would find the headlamp far too loose for running. The lamp adjusts up and down but every time you push the light/power button it moves. I found myself constantly having to re-adjust it. My first impression when I got the lamp was that it looked and felt cheap and the design appeared old and outdated. The 'carrying case' that came with the lamp doesn't even fit the lamp! Hysterical! It's like there was no thought put into this lamp at all. I'm very surprised to see how highly rated this lamp is. I really have nothing good to say about this lamp...again this is from a runners perspective. If you are a runner, don't waste your time or money on this thing! Needless to say, I returned mine after the first run with it.