Is the in dash unit easy to see in the sun? The dealer installed BMW unit is on a goose neck and can be shifted around so glare is not a problem. Also, that unit is not integrated into the radio.
It comes with a small remote unit for setting up the display etc.

Does anyone have strong feelings regarding the "in dash" system vs the "add on"?

I'm thinking of glare, screen size, ease of use. I have driven an X5 with the "add on" and it seemed very easy to use and adequate. I remember seeing posts stating the "in dash" system was cumbersome to use since the controls are multipurpose.

I have been told that if I have an Alpine unit installed that it will void the warranty. To quote "Any non BMW electrical devise hard wired to the car that isn't approved by BMW will void the warranty".