An excellent book on many levels - firstly it is one of the only books I've found, which is available in English and deals quite comprehensively with the Skyline, right from Prince motors roots right through to the R34.
You could also say Butler has got his info directly from 'the source' - the man who was chief of development for the R32-R34 GT-Rs, so the info should prove to be quite accurate.
The book not only deals with each of the R32, R33 and R34 GT-R models in detail, pointing out the major differences between the variants such as 400R, M-spec and V-spec II, Nür, and so on, but also has sections on what to look out for when buying one, how to best maintain a GT-R, and tune it. Of course it is by no means a comprehensive manual on each of these topics but they are useful inclusions.
The book is written fom a UK-perspective, (so the English is perfect), but also includes a section with some international perspective on the cars (such as how they were brought to Australia).
There are also stacks of great high-res photos, most of which are of cars in top condition, and many 'stock' cars, which is nice to see, so that you can appreciate how the cars were originally designed, before all the aftermarket add-ons.
Some of the humour is a bit cheesy... but as an Australian owner of an R33 GT-R I've found this book to be both an informative and entertaining read, as well as good reference material to help understand my car.