Yes, there is a mix of pragmatic advice (with citations) along with stylistic opinions. I think the ES5 version is also quite good. Look at the number of forks, though. I might use this as the basis for a style guide for my organization. I think I'll probably fork it, though, and remove the opinionated bits. I did enjoy the writing style.
Still hard to get used to so many using ES6 already. I'm still not a big fan of transpiling but some days I feel like I'm the only one.