Thnaks for the replies.
I bought dynamic sphere about 10 years ago, but in my mind it is over analytical rather than technical i.e. the diagrams of UPA seemed like a waste of space - much of the start of this book could have been condensed to 1 page.
I'd also agree about training rather than reading; I've got dozens of books. However I wouldn't say that they are useless; they often make me think more about how I train.
I'll consider the book you suggested Sharon - unfortunately many of my insights into aikido are often from reading non-aikido books (possibly because most aikido books seem to be written for people with 0-3 years experience) - Jun, if you are reading, I wonder if you would have a seperate review section on non-aikido books which have relevance to self-defence or aikido.