If you ever watched a courier ride a fixie they generally ride the bike as if you always needed to quickly brake ,to use the handled brakes is too much distraction ,to brake with the gearing unit fixed makes for quicker stops and manuvering while braking is part of the skill,to brake while your weight is forward over the bars just saves on tire tread ,less rubber and weight to the road.I remember seeing a video with Lance Armstrong riding with a group of Fixie riders thru the streets of Austin, a real treat to watch if you can catch it on youtube ,adreniline junkies who know how to ride .