"Reflections..." confronts some of the very troubling issues raised by Calvinism. Rogers' intro explains some important definitions and distinctions that are critical to understanding the arguments in his book. I strongly encourage the reader not to forgo reading the intro. A helpful feature of the book is that Rogers wrote it so that the chapters on various subjects can stand by themselves, making it possible to read just that particular chapter that addresses a specific question a person has, such as "What about Romans 9?" or "What about free will?" Writing the book in this way necessitated him repeating himself a lot from chapter to chapter, which can be distracting if you are reading the book through cover to cover.
Rogers is a pastor, writing as a pastor answering questions he's been asked countless times in his years of pastoral work. For many years he himself was a Calvinist (by the definition in his Intro). However, being forced again and again to answer the questions he addresses in his book, he was led to confront what he calls the "disquieting realities" of Calvinism in relationship to what is the clear wording of many passages of Scripture and the clearly revealed nature of God in Scripture. Eventually he was compelled to abandon the unsatisfactory answers re: Calvinism and to acknowledge the flaws of that theological system.
Writing as a non-Calvinist (or as he says, a disenchanted Calvinist), he is not writing as an Arminian. That is an important distinction to understand.
The book is written largely in a "I Affirm/I Disaffirm" format, stating succinctly what he believes and what he does not believe. He then goes on to elaborate on those affirmations/disaffirmations.
I found "Reflections..." to be helpful in setting out in succinct fashion the troubling aspects of Calvinism, as well as the answers that Calvinists typically give to those issues. Those are answers I've never found satisfactory myself. As Rogers makes clear in his book, neither does he any longer.
By way of transparency, I should state that Rogers is my pastor at Trinity Baptist Church in Norman, OK.