This book IS massive.
It contains 420 hand-crafted puzzles, which were hand-crafted by Nikoli the Japanese Publisher who has been hand-crafting Sudoku for the Japanese for more than 20 years.
The book has also been very well laid out. One puzzle per page, which makes them big enough to put in pencil marks if required. There is an explanation of techniques for the total novice and, if the sudoku don't prove challenging enough, each puzzle page has a space for your time and score. The puzzles are also rated from easy to super-difficult and grouped accordingly.
Considering the price per puzzle from the best quality puzzle-maker available, this book represents excellent value for money and well worth buying.
As an experienced sudoku player, I was delighted with this book and use it regularly.