Literary commentary at its best is a form of synthesis — reading closely enough that separate ideas begin to speak to one another.
The review that merely renders a verdict has done the smaller half of the job. The more interesting work is connective: placing a book beside the arguments and other books it is quietly answering.
Against the Verdict
Recommendation is a service, and a legitimate one. But a review consisting only of recommendation leaves the reader knowing whether to buy the book and nothing whatever about the conversation it belongs to.
The question is not whether a work is good, but what it is in dialogue with.