I've got a GPS unit and I've used it for navigation on some tours. I wish I had done this the last time I was out since I spent time in a number of cities trying to find my way around. On the highway, the GPS is handy because of its elevation feature. I use this often since most of my touring is in mountainous areas.

I don't want to switch to a smart phone for navigation since I'm often touring in areas where cell coverage is not available. The GPS does not have that limitation.