For me, reading books like Quality of Earnings is as much about figuring out what struck Ackman and others to recommend the book to those who work for their firm. Many newer books have similar ways to assess earnings quality. CFA Institute published a good monolith on the topic and other PDFs are easy to find that do a good job on the topic. My favorite book is Martin Fridson's Financial Statement Analysis; A Practicioner's Guide. It is certainly more thorough than QoE but it wasn't 'the first' book on the subject. Even books like What's Behind the Numbers are interesting to read for their case studies, even if they are geared more towards the masses and less toward the analyst. In any event, QoE resonates with investors because it provided actionable ways to assess liberal revenue recognition policies and taken as a whole, provides a framework for thinking about not only earnings quality, but reporting quality as well. For this alone, I would recommend QoE without reservation.