There is some sound advice in here but it's diluted with filler material and what-works-for-you and generalities to the point that I felt it wasn't of value. It's a shame because I'm sure the author knows A LOT MORE than me about being a GM and preparing for sessions. I'd love to learn from him.
For example: There's a whole section on pens and paper vs. electronics but not a mention of any online tools like Obsidian or even Google Docs. Dropbox gets a passing mention but there are paragraphs about pens and pencils.
Selecting your tools has questions like: Are your tools reliable and available when you need them? Do the devices you use have long-lasting batteries? Do your tools work well in those locations?
Some of the best advice is to build templates and put fields on the templates for the things you are weak at, so you're reminded to do them. (Do you forget weather in your scenes? Add a weather field. Forget signature combat moves or tactics for your NPCs? Add a field.) It's good advice. I feel like I read 130 pages for that, and didn't get to see any true sample templates.
This book needed an editor. A ruthless, heartless editor.
There's a really long review here by Jordan R. and he's word-for-word correct.
[2 of 5 Stars!]