I think it must be a very difficult book to translate. It has a lot of poetry, word-play, made-up words, anagrams and the like. It might be difficult to read if you're out of practice reading German.

Yes, how a book looks is definitely important, too. Another thing I love about Moers' books: beautiful illustrations. It must be very frustrating for authors, who almost always can't influence what their books' cover etc. looks like. (And sometimes publishers realize that and the only beautiful edition costs at least three times as much, as happened with the German LotR versions...)