[CRussel]

IME, if a particular book is less successful as an audio book than as a regular book, the most likely culprit is the narrator. Not all narrators are created equal (!), but even the very best narrators sometimes have duds, or books that they just aren't a good fit for. Saying you found a book less successful as an audio book should, therefore, include the name of the narrator(s). And I'd say it should include whether the book was abridged or unabridged but I rather doubt any of us here opt for unabridged by choice.