Hi Dave,
Welcome to the GoPro World!
I've used various mounts for the GoPro and all have worked fine. The sticky mounts are designed for high speed auto mounting, so they will stay where you put them if you follow the instructions. As for shaky cam, yep...some mounts have long arms that transmit vibrations to the cam. I would look for an area on bike that gives the shortest mounting arm for best video.
Some video editing software (Sony's Vegas for instance) has plugins to help reduce the shakes.
As far as "usefullness"? I would save the GoPro for times when the weather and scenery are something you want to remember. It is cool to watch yourself going through a scenic section of road. I've even sped up the video for comic relief.
I've used the cam on my sailboat, my bike, the car, in the pool and home for events like Christmas. Most fun for me are my bike videos.
Enjoy,
david
