My other car has a touch screen Nav interface but I love the iDrive on the X5. Here are the reasons:
1. Using the touch screen is more distracting, you have to take eyes off the road onto the Nav screen while leaning forward to punch in data. iDrive is next to my arm resting on the arm rest and I can juggle my eyesight between the screen and the road without having to co-ordinate it with my hand.
2. The car shake while driving invariably causes you to select the wrong option/character.
3. Smudges on the touch screen
4. No shortcuts to the various screens like the iDrive, you have to go back to the main screen to switch.

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2008 E70 X5 3.0si
Sport | Prem | Adaptive Drive | Tech. | Cold Wthr | Rear Climate | 3rd Row | Running Boards | iPod/USB

2019 G30 530e
Sport | Adaptive | Drv. Assist+ | HK | HOV Access

2018 F83 M4
Comp. | Exec | DCT | First M Car

2009 E93 335i (Sold)
Sport | Prem | 19" 230 | Logic 7 | iPod/USB | Sat | HD Radio | Comfort Access | Heated Seats | Pure Joy

E36 328is GoKart (Sold)
Manual | HK | Trip Comp. | 17" Rims