Ridden it many times, most people just ride from Baden-Baden to Freudenstadt & back. It's a bit broken up after that but you can follow it ok down to Waldshut pick up the road to Koblenz. I use it to go down thro' Switzerland & on to Italy. As said above best ridden quite fast, it would be boring at 50 or 60 & you'd get in the way. Beautiful road with big sweepers, loads of caff's & plenty of corner visibility, no hidden scary stuff. There's a camp site at Buhl approx 10 miles from Baden-Baden.
(https://photos-cdn.tiger800.co.uk/BILD0010c21622c0dd6f7779.jpg)