Navigation System route selection and preferences

I am just getting familiar with the navigation system on the 2010 Prius and I have a question about the Route Preferences selection. When I enter a destination I am usually given 3 routes. When I go into the Route Preferences menu, I can select which route features to follow but there is also a selection for each of the 3 Route Types: Quick, Short, and Alternate. From this menu, it appears that you could select different criteria for each of the three route types, but the system always seems to set the same criteria for each type. So, what is the purpose of having a selection for the Route Type in the Route Preferences menu?

Also, I am disappointed in my ability to get the nav system to show alternate routes. Is there an easy way to get more variety or more selection in the routes that are chosen. For instance, if I want my route to go on a specific road or through a specific town that the nav system didn't choose, there does not seem to be an easy way to tell the system to take that route other than to add a destination along the route. This is quite cumbersome because I don't always know an exact address along the route and putting in a just a city destination will generate a route that takes me through the city center.

I know that route selection has also been an issue with the previous generation Prius nav but any recommendations on how to best use the system for route selection is appreciated.