This is a great book. As an emerging cell-church pastor I particularly appreciated the lack of focus on a "model" cell church. Joel lays out the necessary principles to become an effective, missional, cell-church without espousing a particular method or system. The principles in this book can be ingested and then given individual expression in any community of believers. I would also recommend this book to anyone seeking more information about what a cell church is, or contemplating becoming a relationship-driven community.
Comiskey has done a great job of giving page after page after page of US churches that are making cell group-based ministry work well. These churches are from every background-Pentecostal to Charismatic to Conservative Southern Baptist churches.
This book complements his previous writing, published by www.cellgrouppeople.com and is a good read for pastors looking at the model from the outside. It's also a good read for pastors doing cell groups now because it corrects numerous misconceptions not found in other books.