I've had very good luck with an iPhone 6 in a Lifeproof case as a GPS, using OnX maps.
Battery life hasn't been an issue if running on cashed maps and airplane mode.
What I like best is the large screen size (at least compared to the eTrex models I have used.) Also the ability to easily zoom in and out with the touch screen.
Just make sure you have the maps cashed if you are going to be out of cell range, which is mostly where I end up going.
I still use map, compass and altimeter way more for navigation than my GPS, but really do like the land ownership feature of a GPS with appropriate chip/app.
