Contour pros:
Low profile
VERY easy to use
GPS thing is kinda cool
adjustable settings
Live view for smartphone via bluetooth (you can also adjust camera settings from smartphone)
Laser pointer to see where your camera is aimed
GoPro pros:
More features I believe (in terms of photo timers, etc.)
Better looking footage
Wider angle
more mounting options
LCD BacPac
Contour cons:
not wide enough for good POV
hard to do many creative mounts
GoPro cons:
Can be tricky to operate once it is on helmet
Looks goofy
Can't adjust settings
Both are solid though. I love my GoPro, but I would be just as happy with a Contour.