I have been using a 7" Samsung tablet with OziExplorer and Sygic for years. The screen is easy to read and big enough that you don't need to concentrate to read it. I have it on a suction cup tablet holder with a long arm and mount it low on the windscreen so that the screen is just above the centre of the dash. It does not obstruct vision of the road at all, just the bonnet.
Ozi is fantastic for bush travel. I have many GB of maps of Australia and overseas at scales from 1;10,000 through 1:250,000 and beyond. You can easily put in way points for navigation and then define routes. The 2016 HEMA 1:150,000 map is a good general purpose travel map.
For turn by turn navigation, Sygic is really good and you can buy mapping for any country you are likely to travel in. Navigon is another excellent option.
I am waiting on delivery of my new Grand Cherokee Limited with the Off Road II pack - air suspension, bash plates and the E-Diff - so it will be interesting to see what the navigation system is like.
Cheers
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