Harris asks the questions and gives the comments you might expect, but Nawaz sheds some interesting perspectives on the current debate. For instance when he makes the distinction between fundamentalism and Islamism, in which the first is the result of cultural conservative and traditional ingroup/outgroup thinking, and who see Islamism as "a product of Western modernity born from Western innovation in codifying law in unitary legal systems".
He also makes a good point - and appeal - about what he calls the "regressive left" : "The first stage in the empowerment of any minority community is the liberation of reformist voices within that community so that its members can take responsibility for themselves and overcome the first hurdle to genuine empowerment: the victimhood mentality".
He also makes some historical notes, for instance, that originally, the Quran was not always perceived as the eternal word of God. At one time, the Mu'tazila doctrine, which was the ruling doctrine that the Quran was not the eternal word of God, was "eventually defeated by the Asha'ria, whose views on the eternal uncreated nature of the Qur'an then became accepted as orthodoxy".
Harris also makes some good points, namely that "our moral values has evolved throughout history, and that most of our current moral values are antithetical to the specific teachings of Judaism, Christianity, and Islam". Or, to put it differently, today's believers select out of their books the messages that correspond to their current thinking, and disregard or even reject the values that are no longer relevant, implicitly of course questioning the validity of their books as moral compass.
The concept of the book is unique. Sure, it is a dialogue, but unlike the debates you see on TV, the debaters have time to expand on their arguments, to substantiate them with quotes and references and facts, without being interrupted, while at the same time maintaining the dynamics of a dialogue, namely to be challenged and questioned. A welcome approach!