The book was way too difficult for me (I felt) when I first laid eyes on it but lacking access to any other material I tried to go through it and make the most of it. I'm very glad I took the trouble since the book was a real eye-opener (although at first most of it went totally over my head). Enclosure Joseki gave me the hint I needed to play more "free" and "light", although I guess other books could have had the same result, i.e. helping me to get to 2-3 dan fast, since I was on a roll at the time :-)

It's a nice but difficult booklet, one drawback is that it is far from complete. I feel, however, that once you go through Enclosure Joseki you'll be able to fill in a lot of the blanks yourself, good luck!

The content is very related to Reducing Territorial Frameworks, though the format is more of a dictionary style. I read the book cover to cover and got a lot out of it in terms of how to deal with things like double wing formations. Unlike say Ishida, I think it is not just a reference book.

The books also gave me a much better appreciation of things such as 'this move is very deep, destroying all your aji, but if you don't need the aji you can make it live', or, since we've gone deep here, we will play sabaki. Other books may teach how to play sabaki, but this concentrates more on when. In several situations you are shown that you can either invade or reduce. While it wasn't exactly whole board thinking, it is much broader than I would normally refer to as joseki, most examples covered 1/4 of the board.

The book has allowed me to see a number of moyos as able to be invaded, where previously I would have just reduced. It really drove home just how easy it is to invade a moyo, even a great looking one. It also has added a few moves I'll refer to as tesujis to my arsenal -- e.g. playing a move two keimas away, making miai of playing the intermediate keima or living in the corner. It also showed me enough variations of playing 2-4 underneath the 3-4 shimari that I'm confident playing it in games against stronger players. None of that was explicit, you were just expected to pick it up.

I have talked to two other players who have loved the book, and one who thought it was incredibly boring and the worst go book. To each his own, I suppose. Perhaps I enjoyed it because I frequently lost games by a handful of points because I couldn't read out an invasion, and a reduction wasn't quite enough, so the book was really addressing a weakness of mine.

As for level, the book is almost certainly useless to anybody 5 kyu or weaker. And it is probably still useful at fairly high dan level. In several places the book says 'black can play A,B, or C and then only shows variations for A. You're expected to be getting ideas from the book, not precise details.

This is a dictionary of joseki for attacking and defending corner enclosures. I can't really say much about it, since I haven't tried to read it and I'm not at the level where doing so would do me much good, and I'm not in the habit of referring to it often either.