I bought this book on the basis on one quote on the cover. It says this
"...a marvellous handbook to the Psalms. If I were teaching a course on the Psalms, this would be my textbook." Dale Ralph Davis
As so often, I find that I agree with Davis. At theological college, I read quite a few books on the Psalms; this has better scholarship than any of them. He mentions the trendy theological theories, but stands back and evaluates them sensibly. He mentions form criticism (for example), shows some of the value of it, and critiques it too. It's the best treatment I've read of the academic issues, including Psalm ordering and the formation of the Psalter.
But it's also written as a Christian who doesn't feel he has to tick the boxes of the non-Christian academic world. He writes things like "To understand the Psalms Biblically is, of course, ultimately to understand them in terms of Christ." (p.280) There are whole chapters on Christological and Christocentric interpretation of the Psalms, which was somewhat taboo (and wrongly so) at theological college.
There were a couple of omissions - I don't recall any discussion of the history of composite Psalms (e.g. 89), and the Proc Trust hermenteutic of Jesus as the perfect singer of Psalms only got a small look-in, but they're only fairly minor.
Overall - brilliant. Pastorally warm, encouraging, academic but not dry, well-informed but not in thrall to scholarship.