If you're only interested in getting to where you want to go, you probably need neither GPS or maps. That's how I did my first trip to Scotland in 1998 which included trips into the Highlands. The roads are really well sign posted.

GPS pays dividends when you see a single-track road and on the spot of the moment, think, "I wonder where that goes?" You can explore that road without a thought because when you need to find yourself, the GPS does an admirable job. For those with map and compass skills, a map can do the job. For the rest of us, a GPS provides a lot of assurance. In the last couple of years, I've used Here and offline, downloaded Google Maps. Both work very well.