Yeah, it's good. Working with with learners, I always recommend his books (particularly the ES6 one) as reference once they're past the basics. He's very good and not someone who disseminates much information that isn't just practical explanations of and realistic usecases for spec. Slightly dry, but very concise. This one's [naturally] slightly more in depth, but it's IMO a necessary addendum to previous books/articles -- something that builds on them for slightly advanced usecases. Sibling comment says you'll write better code in 99% of jobs if you don't read it: I don't think that's true at all. Deep copying, for example isn't uncommon.
Referencing the few areas of it where I have domain knowledge I'm impressed. Lots of really good info. If nothing else it's a great starting point for research on various topics.
I glanced through it and it has some interesting stuff, but I suspect you'll write better code in 99% of jobs if you don't read it, and don't know about most of the techniques described
