It looks "fast" standing still. It's not really useful, and actually has a lot of drawbacks in a rookies hands. For example, most people that rock those deep of stems with track drops don't ride in the drops often. The worst for actual safety though is that when they are in the drops and when quick handling is of utmost importance, the riders arms are often extended too far because the drops/stem are too deep. The more extended arms is bad enough, but it often leads to people completely locking out in the drops once they get tired. Which makes them steer like they're driving a school bus, not a sports car.

It looks damn cool, but you also look cool actually going fast .