Really curious to know more about your books. Thanks for all the Hardwork.
YDKJS is a six book series. The first book is definitely beginner material and an overview for the rest of the series. The rest of the books build successively on each other and go deeper and deeper into each topic.
Moreover, the problem with Crockford's "The Good Parts" is that it taught several generations of developers that there's only a small sliver of the language worth learning. I think this is dangerous and unhelpful. I think we should learn all parts of JS, deeply, even the stuff he thinks is "bad". This series challenges the notion that you can just learn a little bit and be OK. It forces you to confront the stuff that you only kinda partially sorta know and dig deeper until you actually fully understand it.
To give you an idea of how these books are different, take "Scope & Closures". In the first chapter, I actually dive into how the JS compiler works and what that means for how it processes your code. We use that to understand the ins and outs of lexical scope. So, basically, it's a simple, fundamental concept like scope, but much much deeper and more thorough than most devs are used to going. You should expect to have all topics in the series covered in that manner, going beneath the surface understandings to deeper knowledge.
The fifth book (Async & Performance) does have chapters 5 and 6 which focus on performance, but more about adjusting your perspective to understand how we can actually deal with performance in a reasonable way. It's a very different treatment of the topic than you're used to.
The biggest thing that will change is that you'll see JS differently, not as some deeply flawed language that we suffer and put up with, but as a beautiful and complicated and nuanced language with an incredible amount of power built in, waiting to be unlocked by those who learn it more deeply. This will infect your thinking about all things you do in JS. It'll cause you to be curious about that hot new JS framework and not just accept the hype. It'll cause you to doubt claims made by others and claimed as true when you can tell now that it's just cult myth.
You will know JS more fully than ever before. That is all I can promise. But I believe that will change the way you write JS, in that every line you write you'll be unable to do so without thinking how and why it is the way it is. You'll solve problems faster because you'll know why something broke and not just fumbling around on Stack Overflow for the next copy-n-paste solution.