It's my understanding that a wheel is providing it's greatest retardation when it is at the point just before locking up.
Therefore modulation and feel are critical as they mean that you can apply the brakes in such a way that the wheel stays in this pre-lockup zone, rather than either locking up and (potentially) losing control, or not applying enough braking force and running into a postbox/similar.
It's my understanding that a wheel is providing it's greatest retardation when it is at the point just before locking up.
Therefore modulation and feel are critical as they mean that you can apply the brakes in such a way that the wheel stays in this pre-lockup zone, rather than either locking up and (potentially) losing control, or not applying enough braking force and running into a postbox/similar.