I am not an aikidoka, though I respect the art and its practitioners. If anything was going to convince me to change style and take up a new art (aikido) - this book would be it.
Much of the essence of the book has been drawn from e-mails sent to one of the aikido lists. In it various people give suggestions on what aikido is, what it isn't, how to do basic movements, the use of weapons, etc. etc. etc. all in a spirit of friendship and co-operation. Co-operation between different 'styles' of aikido - indeed even co-operation between different martial arts. The author has organised, refined and reflected upon these e-mails in a way that enhances their 'message'.
You couldn't learn how to do aikido from this book - but you can get a good feel for the active living spirit of the art - as demonstrated by its practitioners.
Even those martial artists who don't practice aikido would gain much from reading it (for instance there are good examples of how to teach); I would have thought that an active student (or teacher) of aikido would be very well advised to read this.
I enjoy it, and re-read it frequently - one of the 'best' martial arts books ever. (I would give it 6 stars, if that was available!)