Screen can un-dock so that you can use for web browsing, email, internet-connected apps, etc.

Ability to enter vehicle height, weight, length, vehicle specs and destination so that unit can guide you appropriately.  If you have a tall/long RV, this can guide you so you take the route that avoids lower bridges, sharp curves, and related information for most major roads and highways.

Has ability to inform about upcoming elevation changes so you know when a big ascent or descent is coming.