Hi all,
Many of the Cesium devs like to dabble in other things such as contributing to tech books.
Matt Amato (of CZML fame), Kevin Ring (of terrain rendering fame), and me all contributed to a great advanced book on WebGL, called WebGL Insights that is now a free pdf download:
Please check it out and help spread the word! It includes a chapter on Cesium modules/performance/testing, and chapters from lots of other top WebGL players from Google, Microsoft, Mozilla, etc.
Patrick