I'm trying to decide if opting for the Navigation (~$1400 more) is worth it over the UVO radio that is included in the premium package. I don't really need navigation, but this option does give a bigger screen. I didn't know if the Nav option provides better functionality with regard to the radio pre-sets and ease of use like switching back and forth between Sirius and FM or switching between various FM stations. I'm one of those that switches stations frequently and the UVO pre-sets seemed to be less intuitive than the traditional push buttons! (I know you can speak and have UVO switch the station for you) but to me that is yet another added step or two. I just want to punch a button. Any thoughts??