Great overview of various modern heresies (JWs, Mormons, 7DA, Christian Science, Christadelphians, Unitarians etc.).
Each chapter is structured by an outline of the cult's beliefs and historical inception (and usually a look at the founding central charismatic figures -which most have), followed by a kind of systematic approach dealing with the nature of God, the persons of the Trinity, soteriology, and so on, and a view of their own unique claims (usually some sort of accretion) and how they back them up with scripture or perversion of scripture. Each section will include quotations from primary texts by early members and current texts of the sect, sometimes including comments by secondary commentators, then will give a list of bible verses at the bottom of each text which "respond" to their claims. Prompting the reader engage with scripture this way makes their case even more compelling, and makes for a good reading experience.
When reading I'd recommend keeping a bible on hand to follow along in this way.
I found the Seventh Day Adventist chapter to be a little generous, being one of the chapters which seems to have gone through the heaviest revision from earlier editions. Sanders 'takes them at their word', if you will, responding to their recently-published 700 page "response" text. While he deals briefly with "investigative judgement", he does not touch on the more disturbing aspect of 7DA theology which casts Satan as a kind of penal substitution for sin, wherein Christ will cast all the sins of humanity upon Satan as punishment for his role as the originator of sin (although they do not tend to frame this as propitiatory - regardless, it is unbiblical). He speaks of the annihilation of Satan in their worldview, but not their general annihilationism, which is perhaps an equally dangerous and unscriptural doctrine. They want to publicly run from their association with the name of Ellen G. White, while constantly going back to her doctrines in their real teaching.
I also feel like the Freemasonry chapter could have dealt more with the occult aspects of Freemasonry, but the focus on its ecumenism and ethical faults is completely valid, and one which requires less explanation in a short book like this.
Cults and Isms is good as a "warning" to Christians of the errors of these modern sects, and is useful as a surface level guide to primary texts and other secondary critiques by Christian authors. Though, a bibliography at the end of each chapter would have been appreciated as a guide to further reading, but one can be constructed fairly easily by scanning the footnotes and book references throughout. The structure of Sanders' approach would be great to replicate for a more up-to-date work of this kind.