I love equipping my bicycles with coaster brakes. They do away with cables, and simplify the look of a bike. They make for a completely silent ride, without the constant clicking of a freewheel when you coast, and therefore help you tune in your surroundings. They keep your hands free: everything's in the leg work, and along with the single gear, they render the ride more intuitive, and free your mind to be focused not on the machine, but on the landscape, just like when walking. It's a good thing because, since the braking is somewhat smoother, and lengthened, you need to learn to anticipate the terrain, and therefore acutely pay attention to it. Also, they seem to last forever, which lowers the need for maintenance. The only downside would be the risk of a chain break, which never happened to me, but has led me to consider installing an emergency brake on the front wheel of my path racer. I ride it hard downhill at times, and a chain break is a scary possibility, however unlikely.
