Heya, for work I fly around all over the place, I use my phone as my primary nav device, I often pick up a rental car and have to drive to random places, I use Nokia Drive and while it isn't 100%, it is pretty good! I also think it is equally as good as the alternatives on other handsets, as they too are not 100% (In my actual experiences).
My biggest gripe with Nokia Drive is that it tells you to "turn left" or "turn right" at slight bends in the road even when you don't have to turn, the route however is accurate on the screen so a quick glance on the screen tells you that you don't actually need to turn (and there isn't a road to turn on to anyway).
Also it favours main streets (doesn't use back streets much to get you places) but this is typical of just about every nav solution I have ever used.
However besides the little issues I have had, I can say yes the WP8 is "Road Ready" and just make sure any annoying little things you detect, holla @heremaps and use the feedback feature in your phone to make sure it gets addressed!