Is the mount really firmly attached to the bars. i.e. if you flick the camera it does not vibrate? I've mounted my powershot (with mechanical IS) with a spare cat eye rear reflector mount with some bolts and washer to get the spacing right. Its on there pretty firm and even though there are vibrations for bumpy high speed shots, most of the time it's pretty stabilized and not blurry.
I do have a front air fork, but I do have it setup pretty stiffly.
The only problem with the handlebar mount is that you can get affected with motion sickness when viewing it. My wife refuses to be in the same room when I play my trail shots on the TV. I'm thinking of experimenting around with making a chest harness out of an old baby harness that we have. I'd probably look pretty stupid with the big purple thing stuck on my front. But, worth it if I can get some good shots of my sons on the trail.
