The only downside with the harness is shooting one's surroundings while riding. It requires that I sit up and pivot my upper torso which is somewhat awkward and doesn’t always achieve the desired results. A helmet mount would provide a great option as it would simply be a matter of turning your head in the direction of the shoot. Once again, access to the camera isn’t as convenient but I guess there are always going to be compromises depending on one’s own needs/preference. When it comes to riding technical singletrack, I only use the harness for obvious reasons. A crash would certainly spell disaster for any camera mounted on the bars. That being said, nothing is 100% guaranteed as I’ve certainly discovered.