'Armlocks' by Neil Adams was my 8th Masterclass book, and I was a bit disappointed to find that it wasn't up to the same high standards as the other books in the series that I own.
Naturally there is more to cover in a book like this, than a book covering a single technique, (the excellent 'Harai Goshi' by Jean-Luc Rouge, for example), however compared to Kashiwazki's wonderful 'Shimewaza' and 'Osaekomi', both of which are bursting with technical information and myriad practical techniques, this book is the thinnest, both literally and otherwise of the 8 I own.
There are some useful techniques demonstrated, particularly certain players' variations on juji-gatame which one might not otherwise know about.
Adams is obviously an amazing competitor, and his groundwork is excellent, but I was expecting a masterclass on armlocks - instead there is little explanation, and sometimes as few as 3 photos and a very brief annotation to explain a technique.
This is a useful book to have in your library, but if I'm learning a new waza, or trying to understand a point, this is a book that stays on the shelf. I regularly use other books on kansetsu-waza by Kashiwazkia and Komuro, who offer more techniques, more variations, and more armlocks from more positions and in more detail than contained in this book.