From the outset let me say that I've done little reading and little thinking on the topic of the law. Since I've read little about the law, this book has proven to be very helpful in helping me understand some of the discussion. This book targets more of the academy than the church, however, a series churchman would greatly benefit from reading it.
The subtitle of the book sets the purpose of the book well. Ross has written to explain and expound on a particular view of the law, that is, a threefold view. There are other views out there besides Ross', however, this is a work dedicated to the threefold view-ceremonial, moral and civil.
Philip Ross is a scholar who lives Scotland. He is a theological editor who has done work with some of John Owen's works. Unfortunately not much is known about Ross based upon the bio on the book. A few Internet searches yielded little information as well. Despite not knowing much about Ross, I trust his scholarship based upon the names that have given the book a favorable review; Sinclair Ferguson, Douglas Kelly, R. Scott Clark, and Alec Motyer.
Since I have little prior knowledge about books and works on the law I cannot speak to the clarity of the physical structure of the book compared to others. However, I can say that it was helpful for me in following his argument as it was arranged loosely following the structure of the Bible. There are a total of 8 chapters that work from an introduction of the topic to Moses and ends with discussion about Jesus, Acts, and the epistles. There is a very full bibliography and an extremely helpful Scripture index.
From the Finger of God is a welcomed work because there are few books out there that cover the law well. Many people today believe there is no binding aspect of law at all because of Christ. This is at the heart of what Ross cuts to as he tries to dis-spell, the teaching that the law has no regard for a Christian today or that there is no distinction within the law itself.
Ross does well to argue for the threefold division, however, some readers might not ever get to the argument. The book promises (by the subtitle) to be a biblical and theological treatment, however, Ross opens the book with an appeal to a "catholic doctrine" (catholic meaning 'general' in this usage). He appeals to tradition rather than to anything biblical in the opening chapter. It is laced with appeals to The Westminster Confession of Faith and other historical decrees. While I recognize the validity to appeal to history, his appeals would have been better placed later in the text. The second thing that might hold the reader from persevering is Ross' strong covenant language. This is not to say that this language is a bad thing, however, many dispensationalist would probably be frustrated and perhaps not continue to the meat of Ross' work having to comb through this in the early pages of the book.
Having read more on the law in this one book than in all other books I've read, I can say it has been a helpful book in helping me understand some of the conversation. I would highly recommend this book to anyone wanting to dig deeper into the subject. Once through the first chapter the reader will find a thoughtful explanation of how the ceremonial, moral, and civil aspects of the law differ and apply or do not apply today. I look forward to going deeper on this topic in the future and that has been spurred on because of Ross' work in "The Finger of God."