I've been reading "Aikido Shugyo" ( http://www.shindokanbooks.com/shugyo.shtml
) and find it one of the best Aikido books I've ever read. The caveat I would make is that I wouldn't have fully understood it earlier in my career... i.e., there are a lot of comments in the book that sound innocuous but which are meaningful if you already understand what he's (Shioda) talking about.
I would suggest without reservation that it's a book everyone doing Aikido, regardless of style, would benefit from reading.
The one point that I'd make is that Shioda, in his systemitized way, is focusing on "ki" things just as much as Tohei does. Shioda breaks his approach to ki down into components and he refers to ki as a "balance" of the factors that he names. As noted in a previous post, when Shioda's *books* are *translated
* (that's the problem, the translation) to say "Ki is about balance" or "Ki is the concentration of balance", that's actually an incorrect and misleading translation... he means that it is a balance of several different powers and focuses.
I've watched Shioda on a videotape ("Shingi Denju") and it appears that he at some time did a focused study on the use of paths and power applications using kokyu ryoku (in fact, you can see him indicate the full paths several times, using his finger). I was quite impressed with the sophistication and automatic usage of kokyu paths that he showed in instantaneous movement against an opponent's "empty" directions... he was good
. (I have to caveat here that some of his demonstrations are really clever and enlightening, but they wouldn't really work without a cooperative student... but that's the nature of some demonstrations, isn't it?).
Shioda's breakdown of the factors of "ki" is quite clever and gives me a new perspective about thought approaches to the subject, but I also have to comment that his explications are not complete enough to allow someone to just read and understand. In fact, looking at the video of his interaction with students during the demonstration I was commenting on above, I'd say that although he was clearer than anyone I've seen, he wasn't clear enough for some of his students to do exactly what he was doing or to even get the basic idea correct. It would be interesting to see what command of kokyu some of the higher dans in Yoshinkan have... it is, as Shioda noted in his book, an easy skill to lose from the martial arts because it it hard to transmit.
Anyway... I'd recommend the book to everyone. It's a lot about "ki", as are Tohei's interesting books, but it explains more things about ki and Aikido than Tohei's books do. In other words, all these books supplement your overall knowledge of the big picture, but this one is a really good book and has some good discussion topics in it.