I love to use a GPS for running, hiking, kayaking, and sailing, but on most tours I leave the GPS home. On an AC route I really do not find any added value to carrying a GPS. If the route is planned in advance a paper map if ine and a GPS isn't needed and if the route isn't planned in advance I'd still rather use a paper map.

Where I might be inclined to use a GPS is where I am not using roads at all.