ttaylor;
My Garmin has held up remarkably well on my ATV. I did smash the clear screen cover one day, but it was easily fixed with a new one from Garmin. My Lowrance GM100 has an easily scratched screen, so I use clear tape to protect it.
You don't need a Masters Degree to communicate with a GPS. If you want to create a "track back" or move a Waypoint, you may have to study the manual beforehand or bring it along. A lot of my Waypoints had to be moved slightly when the Gov't dropped "Selective Availability" last year, and moving a Waypoint isn't all that intuitive w/o the manual. Setting "track file" intervals is another item that took a while to master. While you may want your GPS to use default settings, it may not be suitable for all trails you ride. I often forget to clear the track file, resulting in loss of track file data. These are just some items that a good reading/understanding of the manual is necessary. It just took me a while. Your results may vary.