The PDC & Rear View camera is worth getting.
It does really make parking that much easier, no second guessing on the distance you are in the front and rear.
The camera adds a decent visual of things back there including parking lines or hitch.

The Nav is quite good too. At first I really didn't like the factory style NAV/GPS but after really using it on our Disney trip we definitely like it much better than the Garmin or TomTom portable one. Before I wanted touch screen but now I can seen touch screen is a big inconvenience, slower and more of a distraction. The iDrive controller for the Nav is the perfect convenience and speed.

If nothing else, get the Tech package and Comfort package.
Oh' Running board looks nice if you like that kind of look.