I've had one of these little beauties for about 6 months now and it is superb. I primarily have it for running, although take it into the backcountry regularly. If running's what you intend to use it for then great - I think it's at the cutting edge. It is balanced front and back, so when you bounce up and down, it doesn't have a tendency to work its way off your head. Also, the light is a "flood" light which means the track in front of you is well lit (I live in an alpine village and run through pitch black forest trails) but best of all you don't have a beam of light doing circles in front of you when you run (see, the guys at Black Diamond did some homework!)
If you use it in a backpacker/outdoors role, be aware that it will go dim after about 2-3 days use and needs mains power to recharge.. so fine if you only want it for a weekend excursion, but any longer away from civilisation and you might come unstuck. I mainly use this light for keeping fit, and overnighters, but I do trust it in the mountains. The red light at the back does come on automatically when you switch white on at the front, so you have to remember to switch it off if you don't want the red strobe. Apart from usual running, I did once find the red light invaluable when I was in the front on a Search and Rescue (SAR) exercise, and those behind me were following the red flashing light in the dark.. In thick dense forest, the navigator was able to "bring me on" to the line of march with his compass. Extremely useful in this situation, even if it was not what Black Diamond probably intended. The Sprinter comes with adapters for most OECD countries, charging port, and you can remove the strap over the head if you just want it single wrap-around. Small and fairly rigid, the BD Sprinter does alot for something that will fit in your pocket. I like mine and recommend it.