GPS gadgets should be discarded as soon as possible in your fell running career, and preferably thrown in the nearest lake, mere, water or down the nearest shakehole. They will never be a suitable substitute for a map and a compass, and the popularity of all this expensive peripheral junk will give rise to the belief that they actually are. There seems to be this crazy technological race where companies are competing to reinvent the wheel with batteries and bluetooth, a race that the budding fell runner should steer well clear of.