Summary: This GPS is a great help for any kind of GPS work you would need to do that didn't require you to be any closer than about 20 feet. Within 20 feet is is inprecise. I've found that the altimeter needs regular calibration to be accurate as well. Too bad it doesn't come standard with an A/C adapter. You'd think with all the money you're paying the least you would get is an A/C adapter!