We're inundated with small data, big data, complex data... lotsa data. And the data is THE story; it should be front and center. Data Flow depicts hundreds of stunning data viz examples. The book is aesthetically beautiful. However, several of the diagrams suffer from low data-to-ink ratios (lots of paint, little useful data)... and many are illegible and printed too small to see or require specific domain knowledge to decrypt.
Where's the data? The book proselytizes the importance of data and there ain't much raw data to be seen (or linked to).
The book designers have forgotten to treat typography as the visual hierarchy for words, the interface design for text. The type treatments and layouts are difficult to read.
Designers, engineers, statisticians, and decision-makers need data viz guidance. This book is not an academic dive into data visualization and needs to follow several of it's own rules for displaying information. But this book provokes your imagination.