In terms of strengths, the author does succeed in drawing out a nice map of monastic history, including the unique contributions of these noted innovators. Overall, it is a coherent "big picture" allowing the reader to distinguish between Jesuits, Franciscans and others. Another positive element is that each chapter invites modern readers, especially non-monks, to consider aspects of historic monastic spirituality for today. This is the richness of Christian and monastic history for the 21st century global dweller.
I do have a number of critiques. First, the author has chosen to begin her study with Augustine in the fourth and fifth centuries and focused on western monasticism. Though Verploegen certainly had to put limits on the study, I think that more on the monastic innovators of the East (Egypt, Syria, Asia Minor) would have helped the study. Second, and related, more detail and color into the lives of Francis of Assisi and Ignatius of Loyola would have also enriched the book. Third, the author's apparent claim that more deliberate ministry and cross-cultural mission does not begin until after the Jesuits (parts 3 and 4 of the book) seems short sighted and misses the missionary monastic work of Basil of Caesarea, Martin of Tours, and the Celtic monks among others. In this sense, the book's title is a bit misleading (from monks to missionaries) as it seems that mission was not part of monasticism until the sixteenth century onward. A final critique is that the book contains no documentation allowing the reader to see on what basis the author built her arguments.
In short, this book is a good introductory work to some important streams of monastic thought and practice.