I used to use a small Magellan eXplorist 200 B&W handheld, on a selfbuilt handlebar mount for my Dual Sport motorcycle. I liked the tracking function, so if I got lost offroad I could just "follow the breadcrumbs" back the way I came.
It had maps only for highways and major local roads though, and eventually wouldn't synch on the satellites. Just too old. No way to update with new maps.
Worked okay for long highway roadtrips.
Tried two other newer handhelds, but their screens are too tiny, and they are now geared too much to geocacheing, useless for me. Money wasted.
Got a big 7" screen Magellan Roadmate for the minivan, and it worked well for awhile. But a couple times, it failed, and had me going the wrong way.
That was when I got my first Android phone and discovered the VZNavigator app. Even it went full-retard once when trying to drive to a county address. Had to go back, take an alternate road, then retry the nav. It worked the second try.
No GPS is i fallible. I still carry paper maps and Delorme books.
Also, does EVERY GPS gadget and app use that same irritating woman for the voice nav? She ain't from around here. She keeps mispronouncing road names.