I just upgraded to a GoPro Hero 3 Black, since it is shooting 1080 at 60 fps (smoother video) and is supposed to have better low light than the Hero2 (I haven't tried it out yet). I have found the GoPro line does better in low light than the Contour. Also, the Contour does not shoot 1080 at 60 fps. I've been using a Hero 2 with my Magicshine MJ-872. The 872 mfger boasts 1600 lumen, but it is really more mike 900 lumen at Max. I can tell you all companies greatly exaggerate on their product's light output. If it sounds too good to be true, it usually is, especially Ebay lights from China. The 872 uses (4) LEDs, has a nice diffuser on it (no hot spots or artifacts) and is around 6000k. It's a little too white for video, so I purchased some diffuser material from B&H Photo which brings it down to 4300kish.
If you want to shoot good video, don't buy a light on price and bogus advertisement. Do your research. You want a color in the 4300 kelvin range. Some of the really bright LED lights are over 6500k, which makes the lighting blue (yuk). Also, you want to find a light where the lens is diffused to get rid of the hot spots are rings (artifacts). You can make a diffuser or a light...I've done that before. You're gonna spend over $100 for a decent light in my opinion. If you're spending $300+ on a GoPro and a Contour, you might as well shell out the $ for a good light.
It is also my opinion that helmet cameras are typically only good for capturing video in smaller walking passages or rooms. Once you get into a big room, the darkness sucks up the light and the picture becomes grainy.
The website www.mtbr.com
does a nice job evaluating trail lights, which what you should use with a helmet camera due to their need for a bright light source.
Here's a video I shot using a Hero 2 and my 872.http://www.youtube.com/watch?v=h2BcC9Zayjk
My email for questions: email@example.com