I have read in several places that some people use Garmin Etrex, Oregon and other models for bike touring. I'm having a hard time figuring out why, since Garmin has a 705 and 800 that are bike computers capable of displaying maps and navigation. Could someone please explain the pros and cons of using Garmin GPS bike computers vs. the other Garmin models which seem to be recommended for hiking and trails? Just trying to learn what might work best for us as we want to tour in this country and in Europe.