When I go on new routes I map it out in mapmyrides or bikely and print the map out. I am more comfortable having a map of the area rather than just rely on turn-by-turn instructions I may screw up. I have a Nuvi but never thought about bringing it. Being able to find the quickest route home may not be valuable if it takes you on high speed, crowded routes with no shoulders. You can't load courses to those things can you?