The properties of polyester make it a heavy line. It sinks faster than fluorocarbon. It also has much less stretch than either fluorocarbon or monofilament. Not necessarily to the degree of braided lines, but it's not far off. It can be a little bit stiffer and have a little more memory, but working with that and around it means that we have a line that will maintain more direct contact with a slowly sinking jig head or small metal casting jig. It's a very clever material and used in the right situation can be a great benefit to certain fishing techniques.
