The financial advice given in this book was good, so I hate to give it a low rating. But as I read, it just kept losing points with me. My big complaints are the writing style, the criticism of other financial experts that I respect, and important issues that the book hardly addressed at all.
The writing style: I got the feeling that Lester was trying to sound cool for the young people reading the book. This book is clearly addressed to young adults, not middle-aged or older people, even though that's not clear from the cover. I thought there was excessive slang and profanity. Maybe some people appreciate this, but it wasn't for me.
Lester criticized financial experts like Dave Ramsey and Mr. Money Mustache, labeling their recommendations as unrealistic and requiring people to eat rice and beans and live in a garbage can. She somewhat attacked the entire early retirement movement (she called its followers "Fireflies") because she doesn't believe that it works. In my opinion, if someone tries to follow the strategy of aggressive saving but finds that it doesn't work for them, there's no harm done. They can just scale back their savings to a more moderate level. And some people do succeed at saving aggressively and retiring early. Why discourage that?
My biggest issue with the book was everything that was left out. While Lester gave excellent advice about US tax-advantaged retirement plans and investing options, she pretty much seemed to assume that all young adults had spare money sitting around that they were wasting that could be redirected into savings. I think a lot of people would disagree. Her advice was to take after-tax income, subtract essential expenses, and save 40% of the rest. What if after subtracting essential expenses, someone has no income left over? This wasn't addressed in a meaningful way. There could have been a chapter about what expenses count as "essential," how to evaluate what you're paying for essential expenses and reduce them, and practical spending tips. (But maybe that would have been too much like advising people to eat rice and beans.)
This book is perfect for the 20-something adult with a high-paying job who needs help setting financial goals and prefers a slangy, conversational writing style. That's a pretty narrow category. Everyone else can probably find a better book.