Answers: When the device craps out (it has happened to me but luckily my touring partner's was working fine), you run out of batteries, the micro sd card gets corrupted (happened to my touring buddy so it was my turn to guide us), the GPS gets stolen, or, in my case, you stupidly have more than 50 waypoints in routes so the device would not route with more than 50 waypoints thus having to rely on your memory and maps for a 17-day tour in Colorado; you live in Europe and want to save money (assuming str is staying on pavement ); you want to save weight or not deal with battery management, and/or you live in Alaska, Yukon, or Northwest Territories where if it is really hard to get lost with NO navigation aids at all.

Of course, ACA's maps are the current gold standard in North America for bike maps. Let us hope that ACA stays in business and that stays the way.

Granted, most of these examples are best when a GPS in not available, but a decent map, like an ACA map, and an accurate bike computer is definitely doable and a lot less weight. That is why I use both whenever I ride an ACA route which since I have done most of them is not much anymore.