I bought a copy of this book in 1976, and have found it an invaluable guide to the dates of the various New Testament documents. Robinson has a very good appreciation of the evidence available from which one can deduce dates for the various books and his general method is very rigorous and logical.
Sadly he occasionally deviates from his method, usually to bring the date of the document concerned earlier than he would otherwise have placed it. This is especially the case for the Pastoral Epistles and the Revelation. It seems that he is attempting to break the consensus of the scholars of his time by placing every book as early as it could possibly be placed. Nevertheless he does manage to show that almost every book in the New Testament should be dated earlier than the conventional dates assumed by scholars, both in the 1970s and in the present day.
The book can be an eye-opener to those who are studying the origins of the New Testament documents. Sadly Robinson slightly overplayed his hand and his results have been ignored. Nevertheless I would recommend anyone making a serious study of the origins of the New Testament to read this book.