Is navigation working off-line now? Last time I checked, it didn't. And Google Maps, even on-line, are quite bad at being a map, with the completely unreliable way of rendering street labels. I've used Google Maps off-line in a pinch a few times, but it wasn't too pleasant of an experience.

(Call me entitled, but I don't think it's too much to ask of an off-line map to offer point-by-point navigation and searching through the DB of addresses and POIs in the off-line map. When you can't do it, I get the feeling someone doesn't want you to use off-line mode, and is purposefully overcomplicating things.)