Eh, I can't agree. I'm sure there is useful signal in there, but the author has a highly idiosyncratic view of the language, recommends tons of "optimizations" based on benchmarks that often aren't sound, and has several bits of code that are simply incorrect.
As one example, the IsClosed function in https://go101.org/article/channel-closing.html is definitely not correct. The author doesn't seem to be aware of the comma-ok form of a channel receive as documented in https://go101.org/article/channel-closing.html -- which would be the correct way.
Many others. Reader beware.