Interesting.. As someone with pretty close ties to what Brad built prior to starting IEX.. I found the book "Brad's resume" as well as propaganda for IEX.
The book should have some sort of "paid advertisement" disclosure.
It is interesting how your opinion seems to be anyone who is critical of this book "works for HFT's"?
As someone with experience of markets microstructure, the book was interesting/insightful and definitely not "utterly without merit".