My initial impressions:

Camera controls / adjustments and displays.

The GoPro is very easy to operate. Once you familiarize yourself with the manual, changing the setting is very easy.
I like the fact that all settings can me changed on the camera.

The ContourHD1080 p controls are also easy to operate. The lasers are a nice addition when trying to align the camera for desired shooting angle.

The magnetic sliding record switch of the ContourHD1080p is easy to operate even with gloves on. I have noticed that occasionally the back cover would pop off as I was grasping the camera to turn it on but I was able to easily pop it back in place while riding.

To change the ContourHD1080p to the 960p mode, I had to use the Easy Edit Software (included with the camera).
The Hi/Lo Resolution switch is set to 1080p - Hi and 720p Lo by default.
I wish that all settings could be done without the use of a computer but as long as you know what kind of video you want to shoot you can set up the camera ahead of time.

Visual and audio indicators are easy to follow on both Cameras but I wish additional record indicators were included at the back of the cameras for when they are mounted in front of you.

Mounting Options

Both the GoPro chest mount and the VholdR helmet mount were easy to set-up. I hope VholdR comes out with a chest mount as well as I really like the kinds of shots you can achieve with this mounting configuration.

Picture Quality

Both cameras do an excellent job at capturing details and colors of the fast changing environment.

Below are two short comparison video taken simultaneously.

GoPro HD bike chest mount cam video in 960p mode

ContourHD1080p bike helmet cam video in 960p mode

Image Stabilization

Not sure if VholdR or GoPro do any image stabilization. Overall I found the ContourHD footage to be more stable but my findings could be a bit bias due to the different mounting options used. I suspect that the chest harness was not tight enough for the top heavy GoPro.
I will be verifying this in a subsequent review by using the same helmet mount configuration.

The 960p resolution settings really helped to take out some of the shakiness present when shooting fast action in 1080p mode.

Exposure Control

Out of the box of the cameras handle the light changes pretty well. The ContourHD1080p is a bit under exposed.  Good news is that the exposure can be adjusted using the VholdR Easy Edit Software to fit your lighting conditions.

Sound Quality

The GoPro has and excellent sound and shines at high speeds, however with the skeleton door cover removed I find the sound a bit too bright (too high in frequency). Much like the GoPro, the ContourHD1080p reproduced the sounds fatefully but at high speeds I found the wind noise excessive. Like Exposure Control, the microphone sensitivity (gain level setting) of the ContourHD1080p can be adjusted using the Vholdr Software. This should come in handy in high wind environments vs. low wind environments or high speed vs. low speed situations.

Battery Life / Charging

WIth over two hours of recording time on both cameras the Lithium Ion batteries were still running strong.
I like using the VHoldR battery charger to charge my extra battery while using the camera and hope that the GoPro guys come out with one as well.

Check out more details on the VholdR ContourHD1080p and the GoPro HD Helmet HERO