I'll be making my first long trip coming from Dallas. How bad do I need a GPS? I already have an Autocom on the bike and an RCU shelf. I've used GPS in rental cars and love them. I'm concerned about the distraction of something visual, though it has to beat pulling over to read the map. Any favorites out there ? I assume they all have audible queues to the helmet. Perhaps it's stuff like memory, color screen, image detail, and programing ease. Any recommended mounting solutions for a 1150 RT ?