I really thought this was well done. We have tons of fighting lately and the book really helped sort things out for me. I like how he goes beyond the typical view that kids fight because they all secretly wish they were an only child (jealousy).
He actually brings to light dozens of different dynamics that can be contributing to too much fighting and conflict. Not all are relevant for every family, obviously--I liked being able to go from section to section, and subsection to subsection, and skip over things that I already knew weren't problems for us but also find many things that would never have occurred to me, that actually are very relevant.
It's always amazing to me when I read a book like this just how much parents don't know before becoming parents. We think we are leaving the traditions of our past families behind, yet, we unknowingly repeat patterns and dynamics even while we think we are consciously fighting against them. The book helped me to see how certain things I do or don't do, as well as my spouse, contribute to conflict.
I especially liked his suggestions for how to change things. Giving your children opportunitites to be generous and helpful toward their siblings at age appropriate levels is something I've thought of doing---and so this really confirmed it for me. He gives quite a few additional practical suggestions that I like. Also talks about what to do in the moment--when the children are aggressive and hurting each other and you need to regain control. Very helpful and informative.