I ordered a copy of this book thinking it was more or less up to date.
However, realising that there was quite a few ales missing from the guide, I had a look inside the front cover to check the date of publication. The last reprint of this book by NWP was in 1999, making the book 13 years old. Although the basic guide to what the hops, malts and barley does to the taste of ales is still useful, the rest of the guide is vastly out of date.
A number of brewers, that have started up since the books initial publication, do not appear in the book, leaving large gaps in the guide for ale drinkers.
There are other guides which are more up-to-date than this guide, which you would be better off buying.
This guide has gone flat.