In my opinion GPS should only be used to read off a grid reference if you get lost. Then with your location, you should be able to use the map to find your way.

If you're going running in adverse weather conditions I reckon you should be sufficient with a map and compass regardless. I do wonder how many people would have a clue what to do with a map if they had to use it.

GPS technology isn't 100% foolproof.

- batteries fail
- technology failure

So it shouldn't be used as a safety net, only to back up proper sufficient map reading skills. When Ranulph Fiennes first went to the North Pole, GPS hadn't even been thought of ( it only became fully operational in 1995). He calculated the degrees travelled to incredible accuracy and was only a couple of miles out when he got believed he was at the pole.