Yeah, I do miss that -- serendipity... my favorite part of travel.
Let me start with directing you to a completely biased webpage:
Garmin nuvis are "best rated GPS" devices
Watch the video.
Then go to something like this
Garmin nuvi 3790T Review (GPSmagazine.com) for a hands-on review by an expert in the field.
Anyway, bottom line is that I like to describe a GPS unit as "having a Native of the area sitting in the seat beside you." You know at all times when & where your next turn will be and in what lane you need to be. And, as you get closer the directions get more and more specific. On the highway, for instance, I have ours set up to say "Rest Area in two miles." And in town, "Red Light Camera in a block and a half." (Same with speed cameras.) The best, probably , is telling it to take you to the closest, cheapest gas station.
Yes, a Smart Phone can do all of that also but... they are too small and, like you noticed, they are not exactly in "real-time." Besides most State now have laws against cell phone use by the driver -- good luck trying to convince them you were not Texting.