Nicely done.
Hands up how many people DO NOT have a GPS device in there vehicle?
->both hands up
I don't! In rural areas GPS units are fairly worthless. Outside of big cities the maps are terrible, even for some of the larger towns (over 3,000 people). For large cities in California and Arizona I use Thomas Brothers guides, which have remained a good product in spite of Rand McNally purchasing the company a few years ago. Thomas Brothers guides have excellent street address indexes, ranges of address numbers on each street, and a freeway on/off ramp index that tells you if your on ramp begins in the right or left lane of a surface street. Once I have an address located on a map, I prefer to do my own route selection, instead of having a computer do it.
I've used software from two different companies for calculating trip mileage prior to taking a trip. Both drew routes that included both paved and unpaved roads that are not maintained in the winter, i.e., not plowed. They don't seem to factor in the slowness of driving mountain roads that are steep and curvy. Often a route that is 50-100 miles longer is quicker than the quickest route shown by the software. Sometimes the longer, flatter routes are more fuel efficient as well.
As for handheld units for use on dirt roads and in the backcountry, the maps provided with the proprietorial software that comes with these units is pretty poor. I purchased a handheld some years ago and found that in order to find your position on a paper USGS topo map I had to carry a 8 x 10 plastic template.
Until someone makes a handheld that will allow me to load in about 10-12, 7.5 minute USGS topographical maps, into the memory that is not proprietorial, I'm quite happy to use my map and compass skills to keep track of where I'm am. GPS units don't always work that well in mountainous terrain anyway, due to the topography blocking the signals of most of the satellites, except those that are almost directly overhead, which don't provide very good information for obvious reasons.
In remote locations putting all your navigational eggs in one basket, which rely on an electronic device, and batteries, is not such a wise idea. Map and compass skills should be solid before setting out on hikes or vehicle trips in remote areas.
If I lived in a big city my opinion of GPS units, especially if I traveled for business purposes, would probably be different. However, I'm not too confident about the route selection they make, due to my experience with route finding I outlined above, and hearing from friends who have experienced some interesting situations based on in-vehicle GPS routing.