This book was very quick to read, and it has accessible language.
It is not a feminist book, it`s a self-help book. As usual, self-help books don't reflect on the societal context (e.g. gendered expectations and behaviors; the harmful effects that your financial situation can have on your relationship), they focus on the inter-personal aspects. This one is like that as well. Because of this, there is no reflection on how miserably low the bar is in many hetero relationships and the reasons behind that. It also does not reflect on what is the difference between a dysfunctional and an abusive relationship. Abuse always starts verbally - this book makes it seem like verbal abuse is a behavior that one can try to change in one's partner. I strongly disagree with that - i think it is a dangerous approach.
This book had many super useful parts - including explanations about behaviors, thought processes, specific phenomena, etc. and lists (e.g. list of different emotions that one can use to name their feelings). I would definitely recommend those parts to others as well.
The examples in this book paint a horrible picture about the fictional couples - they often come off as suffering from abuse, neglect, addiction, or just a level of disfunctionality that makes break up look like a good choice. These were not that useful to me - if you have a relationship that functions relatively well, they may not seem relatable.