i have a chesty, helmet, bar and saddle mount and find they all have their pro's and cons, ill share my experiences below( note they are mine and not a generalisation for everybody, also i have a hero 2 hd not 3 so things may be slightly different on the later version) chesty- very cool if your body position doesnt change much., i turned the clip round so the mount is on top of the camera because every angle from the bottom was too shallow and all i got was the top tube of my bike. i find the chesty is difficult to aim to get the correct view, too high and all you get is sky and too low and you get the ground and top tube only. also if you stand or change body position your vid is stuffed. the video is most stable from this mount though, i put it down to my body absorbing most of the vibrations and not transferring it to the camera. helmet mount. my personal favourite and it gets the whole picture but its a very high view of the action, my head and neck seem to get most of the vibration and allows for a more stable picture i like this one because its like an apache helicopter gun, you shoot what you look at. the bar/ seatpost mount is very cool, allows first hand view of the action but i find it transfers a-lot of the vibrations experienced to the video, nice video from this in my experience but quiet shaky and you only get whats directly infront of the bars/ seatpost. great most of the time but not the option i like. as i say those are my experiences. i love my gopro but in the 2 and a bit years i have owned it i have yet to make a really cool biking video from the footage, i find the editing part really tough and can never seem to get the footage to be edited right for a post ride production. i really love showing people what i have done and most of them (being my wife and son) accept it as a cool way to see what the hell i do with my bike but its a long way from professional and to be honest i think that's why i use it less than i should.
