Looks like a lot of good stuff but it's incredibly verbose and dense. It's important to adhere to standards but I'm not entirely convinced this doesn't end up being counter-productive. But as long as it's a guide and not a 100% "you must follow every little thing" and you can change things then maybe it's not so bad.
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.
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.