I did go through it in detail, and some of us - including myself - have been in several discussions with the author, and yes, I like the book a lot and I did write the endorsement for the cover. Brian also read the drafts and he didn't receive the book's concept as favorably as I did, so he declined to endorse it. Brian's main critique was that the book doesn't go far enough and falls short of introducing custom blocks, Snap's main feature.
I haven't gone through the book with children myself, mostly because my own kids are too old and not much interested in programming anyway, and also because whenever I do something with kids it's mostly to try out and refine new ideas we're working on. We did get numerous requests for help in this forum from parents whose children "got stuck" at some point, and we were mostly able to help them. Most of the "getting stuck" was not the book's fault, btw, but people using Internet Explorer or old iPads instead of laptops. While we still don't and probably won't ever again support IE, iPads should work fine now, but we strongly suggest using a stylus.
Does that help?