Aero handlebars can provide a significant comfort advantage when cycling. They work by allowing you to position your front wheel closer to the ground, thus giving you more leverage against the force of gravity when pedaling forward.  This allows you to go faster with less effort, thus making the act of cycling significantly more comfortable. These handlebars are only useful on a fixed-gear bicycle, though, as they require the wheel you're mounting them to have no sprockets whatsoever. It would be beneficial if you did not ride them on a road or hybrid bike.