I have a CountourHD and have liked it. I mount it on my canyoneering helmet, goggles and a motorcycle helmet. I did break the mount a few weeks ago when I crashed on my motorcycle. I smacked it hard on slickrock and it snapped off. I also have the waterproof case and it seems to work great. I really like how loud the beep is when you turn it off and on. You can hear the beep thru a motorcyle helmet going fast. Overall have no complaints with it.
Looking at the above picture, with the go pro mounted on the front of the helmet how heavy does it feel? I mount my Contour on the side and at times it feels heavy.