As a psychiatrist with 40 years of experience doing psychotherapy, and couples therapy, I’ve used the information in this book as well as other books by the Gottmans to good effect.
One suggestion I would make is that couples that experience emotional flooding that they called DPA can sometimes be helped with mood stabilizing anti-seizure medications and or anti-depressants. Sometimes medication can help stabilize a person’s emotional reactivity enough to take advantage of couples therapy.