Reviewing a volume of poetry is much different than reviewing some genre of prose work. It is so difficult that many literary publications have stopped doing poetry reviews all together. The difficulty is usually presented as four-fold.
First, to use mere prose to talk about poetry is an extremely difficult task. With few exceptions (Edward Hirsch) the best practitioners of this kind of cross-species translation are poets: T.S. Eliot, W.H. Auden, Donald Hall, Dana Gioia. To be fluent and articulate in two mutually exclusive kinds of language usage is as rare as a five-tool prospect in baseball.
Second, it is almost impossible to define your audience. How can you possibly write about poetry in a way that would make people who currently do not read poetry (outsiders) want to pick up the particular volume you are highlighting and at the same time talk meaningfully to those who already regularly read poetry (insiders).
Third, unless the reader of the review is a frequent and habitual poetry reader (and how many people truly are?) there is the very real problem of shared experience and language. Any novel reader knows what a reviewer is saying when he writes, “the characters are multi-dimensional and their quick-paced dialog moves the story well.” But only a “poetry insider” understands when a reviewer says of a poem, “the Alexandrine lines fit the elegy forms the poet has chosen well.”
Fourth, and finally, there is in poetry that indescribable “personal” quality that makes objective standards difficult. Since a poet routinely creates and breaks his or her own rules and since so much of modern poetry is so “personal” in theme, criticism is seen as extremely difficult. I do not “like” this kind of poetry and hence it is bad. I “like” this other kind of poetry and so it is good.
While the first three difficulties are legitimate. The last one is not. Art has standards. If I were to compose a piece of music and Henryk Górecki composed a piece on the same theme and we compared them it would be objectively clear which piece was truly music. While it is admittedly more difficult in poetry, it is clear that what Seamus Heaney writes and what a 7th grader writes for language arts class are as different as oceans and mud puddles. We do not need to be shy about making the same kind of distinction in poetry as we do in music.