I think using a pre-loaded GPS route on a watch or other device in a race is plain wrong, but have no qualms about using the feature on my Garmin that can give an OS grid reference, which I can cross reference with my map. It's not a substitute for map and compass skills, but is a very useful feature for quick relocation in the clag. Fair-play would dictate you should only use it as a backup to get you out of trouble rather than to gain an advantage. Not that it would make any difference where I am in the field!