Of course, some tracks could have been done a little better. For example, the starting video of "History of the language" is 44 minutes. It should have been trimmed to under 10 minutes, in my honest opinion. I would have liked more coverage on the other sections rather than 44 minutes on the history.
I finally understood the various inheritance mechanisms in JavaScript thanks to the coverage on pseudo-classical prototypical and functional inheritance. The coverage on the "Theory of the DOM part one and two" provide insights into the complex DOM model and how the browsers render them.
There are many snippets throughout the video that are enjoyable thanks to Doug's sense of humor. Overall, a good buy for those that are new to JavaScript. This doesn't qualify as a "Master class" but it is very good nevertheless.