I agree with most of the criticism. It's kind of a sloppily written book with odd errors. I can't imagine anyone not familiar with the shop buying the book. The salt and sugar content seem quite excessive. I've never used the recommended 1 teaspoon of salt per quart of ice cream, but did on one occasion use the 1 cup of sugar with the Vietnamese Coffee ice cream recipe, which also calls for sweetened condensed milk, and found it excessively sweet. Usually I use 2/3 cup sugar and a pinch of salt for a quart of ice cream, a system I have worked out and like based on previous experience making ice cream, and find these changes to the basic custard work well for the recipes in this book; I should point out this book uses the same basic base for almost every ice cream.
Another interesting difference in their ice cream base is the relatively small amount of egg yolks compared to most other recipes I have seen. This can be a bit of a problem for the home cook as its easy for someone like myself, who only makes ice cream once a month at the most, to slightly over cook the custard and end up straining out a bit of scrambled egg. If you end up over cooking the base too much the ice cream doesn't set well, so adding an additional yolk or too might be useful to the home cook who doesn't make ice cream several times a day' most other recipes I've read use at least 5 yolks per quart, the recipes in this book require only 3.
The primary reason I bought the book was for some of the shops more famous (or infamous) recipes such as secret breakfast (the bourbon and corn flake recipe). Unfortunately the bourbon ice cream, probably the reason everyone bought the book, contains a major typo and calls for double the bourbon necessary. I think someone has already pointed this out, but its worth repeating as the ice cream doesn't fully set with the appropriate amount and I can't imagine what would happen if you put the written amount; I imagine it would not set at all! to re-iterate the correct amount is 1/4 cup per quart and not the 1/2 cup written in the book. I happened to see the correction on the shops twitter feed around the release of the book, but I imagine no one woulds know otherwise.
I also wish the book include gram measurements as some other books do. I find it very convenient to weigh everything in one or two bowls rather than have to clean multiple measuring cups and was a little surprised that a cookbook by a former pastry chef at a fine dining restaurant did not do so (the owner used to be the pastry chef at Coi in SF a 2 star michelin restaurant). I would also agree with the reviewer who mentioned this book could have been a little more detailed about technique as it appears obvious it is meant for a home cook.
For me the book has served its purpose in teaching me the secrets to my favorite flavors, but I can't imagine someone not a fan of the shop having any interest and would agree with the reviewer that recommends the David Lebovitz book The Perfect Scoop as the best all around ice cream book - Lebovitz other dessert books and blog are great too! I also appreciate the story behind the shop and other details of the book that someone unfamiliar would probably not care about.