Here is a video that a friend of mine(Mark) filmed in his M135i last weekend(March, 2016)... it will show you how nice of a road the Tatzelwurmstrasse is. Unfortunately Mark did not start off at Brannenburg - which is quite narrow and I feel the best part of the drive.
Tatzelwurm Pass (Deutsche Alpenstrasse) with summer tires at about 3°C.
Although the drive wasn't too spirited DSC was on heavy work nearly out of every turn... (indicated in the video overlay)
Filmed with iPhone 6
OBD-2-Data captured by M Performance Drive Analyser
https://drivedeck.de/driveanalyser/
Overlay data created with RaceRender 3.3.5a Ultimate
http://racerender.com/RR3/Features.html
Edited with Adobe Premiere Elements 12