Anyon use the 450 for road travel directions? I have a car without any plug in's. The NUVI battery does not last long enough for realistic use, just a couple of hours. How useful do you find the Oregon without the spoken directions. Will just be used for exploring country roads; no suicide rides on parkways, turnpikes, etc. Rather not get the City Navigator if its not useable nor upgrade to the Montana or Zumo for just that feature if I can avoid it. Thanks!