Richard Gaffin's new book on Paul and the ordo salutis is excellent: clear, pointed, balanced. Despite his strange understanding of 2 Cor. 4:16 and weak exegesis of Rom. 2:6-11, I learned a lot from this short book. His central thesis is that union with Christ by Spirit-created faith is the hub of Paul's thought, from which other spokes such as justification and sanctification sprout. He interacts occasionally with the NPP along the way.
Here's an example of what I mean by clear, pointed, and balanced, speaking of the law in Paul (italics orig.).
It is undoubtedly true that almost always when Paul refers to "law" or "the law," he has in view the body of legislation given by God through Moses to Israel at Sinai, that legislation marking out the period of covenant history until Christ. He is also clear that, as a specific codification belonging to that era, the law has been terminated in its entirety by Christ in his coming (e.g. Rom. 6:14; 7:6; 10:4; 2 Cor. 3:6-11; Gal. 3:17-25). At the same time, however, it seems difficult to deny that in a statement like Romans 7:12 . . . or in Romans 13:9, where several of the ten commandments function as exhortation incumbent on the church, or in 1 Corinthians 7:19 ("God's commandments"), Paul recognizes that at its moral core, the "Torah in the Torah" as it could be put, the Mosaic law specifies imperatives that transcend the Mosaic economy. Included within that law are imperatives that are bound up with the indicative of the creator-creature relationship from the beginning and, so, are enduring because of who God is. In its central commands the law given at Sinai, notably the Decalogue, reveals God's will, inherent in his person and so incumbent on his image-bearing creature as such, regardless of time and place, on non-Jew as well as Jew.
--By Faith, Not by Sight: Paul and the Order of Salvation (Waynesboro, GA: Paternoster, 2006), 31-32.
I think that is exactly right. It strikes the right balances, and says in short compass what needs to be said in summary about Paul on the law (but what would take a book to adequately argue!).