The thing about windshield mounts is a paragraph in the law about obstructed vision or control.. If the GPS blocks any part of your view out the windshield an officer can cite you for it.. Of course I note the Rear View Mirror also blocks part of the windshield (Usually exempted in such laws) and State Park annual pass, Vehicle emissions inspection stickers and a whole lot of other stuff often REQUIERD by law.. Some times the stickers are exempted, sometimes not. (Parking pass for the Legislative parking lot...)
Ok, when I worked for the state we put our parking passes on the back side of the Rear View Mirror where they did nto obstruct any additional space. but that's how I know this. .....
I use a computer with dongle, it sits on a center table in the motor home, On-board map means I'm not reliant on a cell signal, The dongle sits in a dash tray, out of sight, Out of mind. NO obstructed vision.. MUCH MUCH larger display is far easier to read with a glance (On/Off route) when in the motor home.
In the car I use the phone but I pre-load the route map. However if anything causes me to leave the map program.. I may be screwed when it comes to getting it back.