To make the most of our individual lives, to live into the promise of this gift, we enter into community with other people. In community, my weaknesses can be accented by your strength, my blind spots offset by your perspective, my despair raised by the hope and love of my companions. As all those jokes would indicate, we often do things slowly, with a great deal of discussion and over long periods of time. Ours is not the most efficient way to organize a church. If you are looking for efficiency check out the Mormons or the Catholics.
Polity is akin to the word politics and refers to church organization.
The Presbyterian form is similar in that it is top down, it is distinguished from the Episcopal form by the fact that the church hierarchy is made up of panels that either include, or are entirely made up of, non-ordained persons. Under congregational polity each individual congregation makes all decisions of significance and any initiative from an organizational hierarchy is seen as non-binding upon the local congregation. There are clear parallels between the autonomy of the local congregation and the freedom of belief granted to individual members in this tradition. In our covenantal tradition, individuals discern their own understanding of what is ultimate and true in the world and then enter into a community to maximize their humanity. I believe it is a good way to do things.