I'm into tech so I opted for pro nav even though business nav already came with the car so that I don't miss out on anything
Also, i guess it depends if you are into tech or into storage
My perspective - iDrive makes the interior look better as well esp. the pro one. Also, nav is a must have for me. Besides, with the phone integration option you can make calls using center console screen, check msgs & emails (even get the car to read out to you) and watch DVDs while waiting for someone etc..