I've not used one for any purpose, but they are really popular as controller screens for flying drones due to their bright screens. A lot of threads over at mavicpilots.com about them if you want some reviews. Not sure all models have the same bright screens.
What app will you be using for navigation? If know the app you're going to use, you might work back to an appropriate tablet. Some apps work really well in Android while others work well in iOS. I think the Triplteks are all Android.