The rock on both climbs is generally excellent, the best that I have ever encountered in the Dolomites. It is a world of incredibly featured rock, pale and steep, brimming with holds even on the most intimidating and exposed faces. It's an area that will doubtlessly lure you back again and again. Even if you have been put off climbing in the dolomites in the past because of dubious rock quality and meandering, difficult to follow route descriptions you should consider giving this area and guidebook another chance.
In reply to AlanLittle:
The Frisch - Corradini is supposed to be fantastic too, and a very logical line. However it is somewhat harder, more sustained at V rather than IV. I was there with clients who were not super experienced rock climbers so the Castiglioni-Detassis was the better choice for us at the time... it was a full day!
I would love to go back for the Frisch-Corradini though, and am planning a return trip next September so maybe.
Hope you enjoy the area and the routes! All the best,