gregmcc:
No doubt GPS apps on a smartphones work well, the big drawback is they suck the power.
Nothing like a dedicated GPSr
The garmin one on the samsungs works well. It is basically a garmin GPS. The GPS built into mazda cars is also really good I have found, although not sure who provides the maps for it. As good as my tomtom, and it is voice controlled which is a bonus.