Been there last week, funny to find a "via ferrata" such far away from the alps. Our daughter had some fun and angrily refused any kind of belay ;-)
One should stress that the walking / hiking parts prevail. The upper part of the trail is mainly ment to bring you to the restaurants on the hillside; from sportive point of view you better turn around after the last ladders (part "3" in the picture http://www.klettersteig.de/Klettersteige/Bilder/1452-2.jpg ).
Compared with the Calmont nearby the "Rheinkletterstieg" offers more scrambling, more traffic noise but less (!) exposure IMHO.
"After the first glass, you see things as you wish they were. After the second, you see things as they are not. Finally, you see things as they really are, which is the most horrible thing in the world."
--Oscar Wilde on Absinthe