I have a copy.
It is full of good ideas.
Some of the specifics such as the exact reductions for null move search are improved on by new techniques (see stockfish).
But the fundamental outline of the book is excellent.
He has some really interesting ideas in the book.
One example:
Replaceable evaluation functions for different game stages.
If you are planning to write a chess engine, it is worth the purpose.
One caveat ...
A large portion of the book is appendix which has results from analysis and things like that which are not really programming stuff, so the total volume of the book is not great.
If I did not have it, I would probably buy it, though.
Other suggestions:
1. Find a backup of Bruce Moreland's programming page and read it
2. Read Dr. Hyatt's papers. They are very good.
3. Read Ed Schroder's chess programming pages. Especially helpful for evaluation.
4. Read specific techniques from the chess programming Wiki.
If you want to study a simple chess engine, I
highly recommend sungorus:
https://sites.google.com/site/sungorus/
Olithink is a bit puzzling at first, but you will appreciate its beauty more and more as you examine it:
From here:
http://home.arcor.de/dreamlike/chess/
Get this:
http://home.arcor.de/dreamlike/chess/Ol ... 32.src.zip
IMO-YMMV