Plastics are cheap and have a life-like feel that hair and feathers can't match. They're also easier to rig weedless (see the crappie slider.)

On the other hand, hair and feathers have better action in the water and are more durable.

That being said, I'm more of a "marabou & chenille" guy. The main thing, though, is finding the fish. Then, put the jig you have confidence in right in front of their noses.