1. Complex-conjugate poles of the closed-loop transfer function lead to a
step response that is underdamped. If all system poles are real, the step
response is over-damped. However, zeros of the closed-loop transfer function
may cause overshoot even if the system is over-damped.
2. The response of a system is dominated by those poles closest to the origin
in the s-plane. Transients due to those poles, which are farther to the left,
decay faster.
3. The farther to the left in the s-plane the system's dominant poles are, the
faster the system will respond and the greater its bandwidth will be.
4. The farther to the left in the s-plane the system's dominant poles are,
the more expensive it will be and the larger its internal signals will be. While
this can be justified analytically, it is obvious that striking a nail harder with a
hammer drives the nail in faster but requires more energy per strike.
Similarly, a sports car can accelerate faster, but it uses more fuel than an
average car.
5. When a pole and zero of a system transfer function nearly cancel each
other, the portion of the system response associated with the pole will
have a small magnitude.