Why is it some helmet cams are bumpy and some are awesome

Hi,

Since i'm going to ski next week, and will try for the first time my helmet cam on the slopes ...

I was wondering why the footage of some some helmet cams is really bumpy
http://http://www.youtube.com/watch?v=YVLCUNIhmHE

And some are just awesomeness
http://http://blip.tv/file/605530

Ok, the quality of the cam itself probably isnt the same!

But is it the type of snow?     hard/prepped pistes   vs.   soft smooth powder ?

Or does the awesome ones have some sort stabilisation?


Hope some one can help me here :)

thx