I do understand why people want to use the navigation system they paid for and that has a big screen. But, really, a good phone holder, preferably with wireless charging, and a properly configured phone with google maps is simply a better navigation solution than the built-in one.
x2.
Car navi is several years behind with new roads updates.
When I don't have it in Sprinter, my 2014 E class will not show Phoenix. 303 freeway that was started around 1995 and completed in 2011.
Than the commands are lousy. Quite often I come to multi-lane street crossing and my car navi is telling me "turn right in 50 feet".
So I go straight to next street, when 20 ft later the navi tells me "turn right now" what would be turning against the traffic on multi-lane street.
Than entering street address on car navi is long process.
With my android I plan the route on my computer, with legs and stops , what takes me seconds and allows for route adjusting and text the link to the phone, so I can open it any time I need. Quite often car navi will route me around the neighborhood, becouse there is closer freeway ramp, when using city streets can save me several miles.
I have prepaid android, so avoid data on the road, but if there accident on my way, I fire it up for live traffic.
Google maps will find address where the house is not build yet.
A little bit inconvenience on the road with need for charging, as batteries go very fast, but my android give clearer voice commands than my E class does.
Lastly when I plan long trip and want it on the car for long time, I can manually enter the point of destination car navi can't find - using my android as referall .
Did I mention google has free updates every single day, when MB updates cost $250 ?
The only advantage of MB navi is that it is having gyroscopic backup, who will guide you in underground garage... till it gets lost after few turns. .