Hello all, first post here, current BB Tour owner, soon to be a D-X owner I have a TomTom GPS that has a very out of date map. It will cost me $70 to update it, and for that amount of money, I might has well pony up the $30 more and get a brand new unit. But, after looking into the new Google Maps Navigation feature, I'm not sure I will need a stand alone GPS unit, once I take delivery of my D-X. What, if any, features would I lose by using my D-X as my primary nav device vs. a dedicated GPS like a TomTom or Garmin Nuvi? Has anyone else made this transition?