Toast is right, but there's a few other things to bear in mind as well.
The GoPro 2 has pretty awesome low-light/nighttime picture too.
I've heard GoPro users complain about being able to feel the camera on the side/top of the helmet and that it's heavy, uncomfortable, and that they can feel it dragging on their helmet. That makes sense, it's about as aerodynamic as a brick. The Drift on the other hand isn't as heavy (that I can tell) and is much more streamlined, I've never seen a Drift user complain about feeling it in any way. Only time I know mine is there is when it bumps my shoulder when I do a shoulder check.
The mic issues with the Drift are pretty well noted, and it seems that part of the issue may be in the mic itself, as someone on here recently commented that they used a different mic and got pretty good results.
Then there's the price. At $300 the GoPro (motorsports edition) comes with a couple mounting bits, the camera, and the skeleton case. To vlog with it you have to buy the microphone seperately. If you want to be able to review your vids or easily check the angle of the camera with the GoPro you'll also have to buy the little LCD backpack thing at $80.
Or you can go with the Drift. The drift will run off USB power while recording, I don't know if the GoPro will or not. That means your recording time is limited only by your memory card. It takes a little effort to set up on a bike, but if you do it right it's pretty sweet. The $320 package deal from MyPOV360.com (may be available elsewhere, I dunno) comes with all the mounts you need, the remote that has a 50/50 shot of working properly when you hit the button, and the microphone which may or may not work out for you. The camera itself is reasonably waterproof (I've ridden with my stealth in blinding rain with the rubber boot on it and it came out fine,) has a much easier menu system to read and understand, a rotating lens so the exact placement of the camera isn't terribly important, it's very easy to fix (and screw up...) the vertical alignment, and an onboard LCD display.
Personally I think that yes, the GoPro has better picture clarity, but that's the only benefit to using it. It costs more to get a camera that's bulkier, more noticeable to the rider, and has a limited recording time.
If all you care about is how clear the picture is (day and night), go GoPro. If you don't have money to burn, or actually care about whether or not the colors are correct, or want a camera that's easier to use as well as less draggy, go with the Drift.
It should also be noted that a $15 -10db pad and a cheap extension cord for the mic will erase all audio issues with the Drift at the expense of something a little bigger than a AA battery that needs a home in the helmet.
