Ligon Duncan, President of the Alliance of Confessing Evangelicals, said that Waters' Justification and the New Perspectives on Paul is, perhaps, the best single book-length introduction and critique of the New Perspective on Paul.
I doubt Duncan's remark. In the section 'Old Testament versus Second Temple Literature' (p.156-157), Waters wrote that N. T. Wright does not differentiate the Old Testament from the apocrypha and other noncanonical literature while constructing Paul's worldview. Therefore Wright "does not do justice to those distinctions that Paul himself employed to speak of this literature. Paul accorded authority (and that of Scripture) only to the books of the Old Testament (2 Tim. 3.16). There is no indication that he regarded noncanonical books as having any comparable or intrinsic authority." (p.157)
A couple of problems here. First and most fundamental problem is that 2 Tim. 3.16 does not tell us which the range of literature that Paul considered authoritative. To identify the Protestant list of Old Testament books as Paul's canon list is anachronistic. A damnable heresy in historical studies.
Second, how does one determine which literatures did Paul seen as authoritative? Waters did not explain this. Does the fact that Paul cited or alluded from certain sources would simply means that Paul considered them authoritative? If that is the case, then Paul must have thought Menander's play Thais ("Bad company corrupts good morals" in 1 Cor 15.33) and Cleanthes of Assos ("For we are indeed his offspring" in Acts 17.28) authoritative and as his scripture.
Both Menander and Cleanthes of Assos dated back 4th and 3rd century BC respectively. Besides these two works, Craig Evans has helpfully provided a list of quoted, alluded, and parallel sources found in the New Testament which many of these are not from the Old Testament. (Craig A. Evans, Ancient Texts for New Testament Studies [US: Hendrickson, 2005], p.342-409).
Of course the fact that Paul quoted from these sources does not by itself means that Paul considered them authoritative. But this certainly blurs the scope of Paul's canon list. Unless Waters provides us the criteria on how to separate which sources Paul considered authoritative, he does not do justice on Wright, not to mention on Paul himself. Here we have two reasons to question Waters' starting point which is not only problematic but wrong.
Previously we have Fesko with his claims that his work engages Wright's view, which we currently know it is not. Now we have Waters whose work is considered by the President of the Alliance of Confessing Evangelicals as one of the best critique on the New Perspective of Paul, which we presently know has a problematic and wrong starting point. And both books are published by Presbyterian & Reformed Publishing. If these two books are considered the best works by them and their cohort that engage Pauline studies, then I doubt I would want to get another one on this subject from them.
I have developed the impression that the main disagreement that the so-called Reformed and Evangelical groups have with contemporary Pauline studies is not so much on interpreting Paul's letters but at a more fundamental level which governs the interpretation: the approaches (which and what criteria?) to find out the past.