I have a Garmin Etrex 30, had it for ages and love it. I use the basecamp thing on my laptop so I can up load the routes I've taken onto my topographical map. The maps is where the money went.. But, for what I use it for it's proven invaluable.
It was even better when I could overlay them onto google earth, but once I upgraded to earth pro I lost that
But I can use coordinates and see what's what.
It's gotten us out of the poop a few times, opened up possibilities with trails we might have found but proximity, hey that trail we followed last week? Yeah looking at my laptop - maps etc, there's a trail we use 20 feet through those trees or w/e.
Marking way points and finding them again etc.
it turned out to be the complete opposite to what I bought it for, the bread crumbs hansel and gretel thing to get out of being lost, instead it's sent me on journey of discovery and knowledge.
There's no substitute for having half a clue of where you actually are and I've never lost sight of that, I use my GPS along side that for sure.
It just saves a load of time.