In my opinion all the mentioned units are very good at recording video
The reason I went for the GoPro is that the modes can be changed whenever you like (video, pictures, time lapse, resolutions etc) unfortunately some other units (like the Contour) can't be changed without being attached to a computer.
The other thing I like about it is that all the GoPro Hero 3 series can utilize a mobile phone app to control the unit, and see a live feed of what will be captured.
The top of the range Contours also have an app but I found them to be more pricey then GoPro.
I believe the Drift receives all the same details that the apps provide on the small screen on the side of the unit.
To sum up, if you're only after a unit to capture video the Contour is nice an easy to use item, just a slide to switch on or off. The GoPro and the Drift by comparison both have buttons to utilize their functions.
So apart from price these were some of the things I considered before making the choice to purchase the GoPro.
Cheers
Shiney