I have used both on my helmet, a GoPro 960 and a ContourGPS.
I like that the Contour is sleek on the helmet, as compared with
the GoPro that sticks out.
ContourGPS mounted on an ankle strap using the goggle mount
then attached to the side of the helmet.
http://www.youtube.com/watch?v=GGDyJh1bGR4
http://www.youtube.com/watch?v=IFj80L5e3no