I recently skimmed through it, for maybe 30 minutes, but it reads like an introductory text. Maybe useful if you've never heard the terms "replication" and "sharding" before, but not all that useful if you actually have to build a scalable architecture and you don't want to shoot yourself in the foot by designing something that's either too complex or that's going to fall over the moment traffic doubles.
I read through it and really enjoyed the way it was both a tour of the landscape, but also went into real distinctive attributes of why the 10 different X (message formats, pubsub architectures, etc) exist and what each one gains and loses by the choices it made.
For a more prestigious review:
“This book is awesome. It bridges the huge gap between distributed systems theory and practical engineering. I wish it had existed a decade ago, so I could have read it then and saved myself all the mistakes along the way.”
— Jay Kreps, Creator of Apache Kafka and CEO of Confluent