Guest Jon - yes, getting from town to town is a doddle. That's never been my problem. The reason I use a SatNav is to find destinations within towns, or destinations (like prisons) which aren't signposted in quite the way you'd expect.
However, a useful by-product of the SatNav is that it gives you a fairly accurate estimate of how much further you have to travel and how long it will take, and it adjusts this when and if you're stuck in a jam. As well as being able to calculate an alternative rapidly if the route you're taking is blocked off or jammed or otherwise not free-moving.
Mine does have a few blind spots, however, where there are new roads now open...despite updating regularly.

Anne