I haven't taken a look at it yet. Can you summarize what it offers that Donovan & Kernighan's "The Go Programming Language" doesn't? (Sincere question, not being snarky.)
I will highlight some key aspects of my project:
I teach computer science in my free time in a small non-profit organization. Most of the students have no knowledge at all in the field. I wanted to write a book that anybody could use, not only to learn Go but also to learn how to code from the beginning.
I tried to explain every notion by imagining a student with no prior knowledge. I also added content about some key notions like encoding, some basic knowledge about what a computer is made of, what a pointer is ...
I also tried to keep a practical approach, with many examples. I also added a lot of drawings and screenshots. Images are sometimes more efficient than long explanations (this what I learned when I began to teach children).
Keep me updated if you have some time. I would love to hear your feedback ;)