I have a Garmin Nuvi in my car. It's good for that application, but not for bicycling.

I have a Garmin Vista HcX on my bike. It has its uses. I bought it intending to load ACA's waypoints and routing into it, since I was taking an ACA route (the Lewis and Clark). It didn't work for me. The ACA files have every waypoint under the sun, and all the alternate routes.

I ended up just using the maps. However, the GPS did have some uses. It got me from the Amtrak station to my motel, and from my motel to the start of the ACA route in Portland. It found me motels a couple of times and a restaurant for breakfast in Walla Walla.

I'll be taking it on tour again, but next time I'll program the routes myself, using a combination of the ACA maps, Google maps, and Garmin's MapSource software. I'll plan my route several weeks in advance. For the Lewis and Clark I was still learning about waypoints, routes, the ACA files, etc. up until the last minute, and I was hurriedly trying to program routes, rename waypoints, etc. when I was also assembling my gear, checking my packing list, etc. I was harried and rushed and didn't do a very good job. I think the biggest problem was the ACA files. Next time I'll load them into MapSource on my computer, but only as a tool to help me program my own routes for downloading to the Garmin.