I really wanted to love this book: Running Lean is my favorite book for introducing someone to Lean startup as it provided scripts an aspiring practitioner could put to use right away. Ash didn't completely abandon this approach, but unfortunately he also added in too much extraneous commentary for my liking. That being said, parts of this book greatly advanced my thoughts on how to apply lean within my org.
The Good:
Ballparking estimates: we've all heard the PM interviews questions about "how many ping-pong balls could fit in a VW?' (I never understood the point before) Ash introduces a way to come up with reasonable estimates that can be used to check the potential for a plan.
Explicitly calling out constraints. Its common go try to solve problems by throwing more resources at them. ("If we just build this one more feature"). A business' success is tied to leverage and achieving more with less.
Sprint meeting agendas! While I've previously run experiment planning and review meetings with stakeholders, I was excited to see this structure and plan to incorporate it in future meetings.
The Not-Good
The metaphor of the Customer Factory and measuring throughout was meh, and the middle chapters of the book just rehashed Pirate Metrics. If you're reading this book, I assume you already have the fundamentals down. If not, go read Running Lean.
I found myself skimming through about a third of this book, waiting to find nuggets of practical application, which is where Ash shines.
In all, I'm glad I finally forced myself to finish this book ( I started it 8 months ago!) there's a lot of good material in here, it's just sprinkled in with a lot of extraneous background I didn't need.