I am really of two minds about this book. For a specialist, it is full of excellent and erudite discussions on sources, redaction criticism, literary criticism, and socio-historical evaluations. There is some effective exegesis, and although I do not agree with all of Stanton's conclusions, his reasons are sound and he engages well with large amount of scholarship.
However, this book is only for the specialist. As a PhD student, it was helpful to me in many ways, but I'm not sure I know a single person I could recommend this book to, and I know a lot of people. Is this a fair criticism? Maybe not. After all, the specialist is really the only audience Stanton intended.
The book also suffers from being so focused on certain redactive and social aims that it has nearly no discussion at all on things like orality, Jesus traditions, the potential of actual eye-witness testimony, etc. Maybe this also isn't fair, as those things became a greater focus after Stanton wrote this book. But even in his time, they should have been obvious factors, and he makes almost no use of any of these important issues.
Overall, for what Stanton was driving towards, I think the book is very effective. However, as it is limited in scope, it becomes limited in future use.