I have a GoPro Hero camera for use in my racecar(SCCA Solo2 autocross car - slalom racing around cones, much like ski racing, but with cars & traffic pylons). I bought it from a friend who has a Real Race Car - a D Sports Racer, 1000cc motorcycle engine tubeframe thing, lots of vibration - it did not work well for him. The vibrations would make it do funny things.
For me - sedan based car (1968 BMW 2002), it works very well. For the price - ~$200 for all the junk I got (I paid $100, slightly used), it is _awesome_.
First round with it, I used the suction cup thing and attached it to my helmet. Worked great, was interesting to see what my head was doing relative to the car.
From there, I welded a vertical post to the harness bar, used one of the 3M adhesive deals to stick the mount to, and the camera-holder (a waterproof thing) clips into it. Example:
http://www.youtube.com/watch?v=OeqxsE32px4
The video quality is affected by Youtube a bit; the original is quite a bit better. Sound quality does not really change - it was designed by surfers, and the camera lives in a small, waterproof plastic box. The sound leaves a little to be desired - I can tell, listening to that video, where I was on the gas, where I was on the rev limiter, etc - but the sound capture is not-so-good.
It is a VERY simple device. It has two sound capture settings (gain?) - low and high. If I put it on "high," it just makes noise. If it is on low, well, you can hear it - not great.
THAT SAID, for my purposes, it is awesome, and very much worth the money. To get anything _truly_ better, I'd be spending $600 or more.
It comes with all kinds of stuff to attach it to helmets and whatnot; I'll post some sled/skiing videos once the snow flies.
In a way, you get what you pay for. It is inexpensive.
On the other hand, the "other" primary brand that most autocrossers use (the kind of "racing" that is) costs ~$700+++ - and the sound capture IS better. Those units DO integrate with data-analyst stuff. Those units DO have a LOT more going for them, they have lots of neat features - multi inputs, frame in frame, etc - but ALL I WANT is in car video with enough sound to let me know where I'm screwing up; and it works _great_.
My friend with the DSR had issues due to vibration - the DSR type cars have no rubber whatsoever (beyond tires), and the high frequency vibrations of a heimjointed car with 12krpm motors seem to confuse the GoPro (and it seems to be an issue with the other brands, although maybe not so much with the digital capture systems - $$$$, Chasecam.com et al).
I have not yet used it on a sled, but I expect zero issues mounting it to my helmet and snowmobiling/skiing - it is a really cool device, as long as you're not mounting it on a high-vibration vehicle (snowmobiles don't count - they seem buzzy, but go drive a Real Race Car before solidifying your definition of "high vibration"). Helmet mount - no problems at all.
I'd buy one full-pop. I was planning on it, then I found that my friend was selling his at half price - sure!
I'm really happy with it. ONLY complaints I have are sound quality (ehh, does the job I need it to) and the simplicity of it - you can tell it to remember which mode it was in the last time you turn it off; for me, video mode (it can do stills and 3 photos per shutter-click). So, you turn it off between runs, and the next time you turn it on (you don't have to take it out of it's little case to turn it on, there's a sealed pusher for the buttons), it remembers it is in video capture mode - UNLESS you change the batteries. If you change the batteries, it reverts to "stock" mode, and the next time you turn it on, you have to remember to put it in "remember last mode" setting.
No big deal, but you WILL forget and wind up with a bunch of still pictures.
I have a 1G card, and I've not even come CLOSE to filling it. My roadracer friends say that they get about an hour per gig - it takes up to a 2G card.
Worth the money. They're cheap. They're not super sophisticated, but they capture good video (the in-car footage is as good as any televised in-car you might see if you plug it into the TV/run it off the computer - Youtube's compression kills the quality), the sound is so-so.
I don't think there's a better $200 solution out there, though, and the waterproof cube is designed for surfers - should work fine on a sled.
Using rechargeable batteries is a good idea - if you use off the shelf alkalines, they die fairly quickly - about 45 minutes. The rechargeables last longer - longer than I need, anyway, maybe an hour? I've not used it in truly COLD weather yet, but cold kills batteries, no matter what.
1.5 thumbs up overall, 2+ thumbs up when you consider price.
I'd buy it again.
Iain