Personally, the handbrake system is simple, direct and has an excellent track record. I have been able to emergency stop and maneuver hundreds of times with them. My experience with using the back brake only is somewhat less successful (before I learned how to use the brakes correctly and when I had a coaster brake bike). The brakes do not require pressure from your arm but rather a gripping motion from your hand, thereby not interfering with the arms ability to steer since one can in fact steer the handlebars by clutching the brake itself and the fingers do not steer themselves. So, yes handbrakes are not only the simplest solution but are safe as well.