Yeah, correct me if I am wrong, but I believe Preferences can be set only for the SELECTED route. You have to actually pick a route before you can choose Preferences for it, or to Preview the animation. I don't think there is a place to set the preferences globally (but Garmin does :P ).
I think that's right. My Lexus navi system usually gives me three choices, shortest route, longest route, and most inconvenient route. I opt for the shortest route and hope that it gets me there, which us does 80% of the time. When Lexus claims that their navi system is the most advanced ever, they must not have looked at Garmin. But that is another topic! :D
The Lexus Nav system is not nearly as good as the system on our previous car, '06 Acura TL. Had we known of its deficiencies, we might not have gone with the Lexus. Personally, I couldn't imagine driving a new TL, but my wife really relies on a Nav system in her work (real estate).