First of all, I would definitely say that if you are just beginning to learn how to solve Sudoku puzzles, I strongly suggest that you do not buy this book. Instead, I would suggest a book which focuses almost entirely on the standard 9x9 Sudoku puzzles, and which starts with easy puzzles before progressing to more difficult ones. The Big Book of SuDoku 3 starts right out with difficult puzzles, and the puzzles only continue to get harder and harder as you continue.
If you are an experienced SuDoku solver who is able to solve all but the hardest 9x9 SuDoku puzzles without too much difficulty, or if you have grown a bit tired with the standard 9x9 SuDoku puzzle, this is a great book. For me, the most appealing feature of this book is that half of the 200 puzzles in this book are different from the familiar 9x9 Sudoku. While the Maxi (12x12) and Super (16x16) puzzles are just larger versions of the 9x9 puzzles, the Jigsaw, Duplex, and Triplex puzzles actually require the solver to use different solving techniques than are used for the regular puzzles.
Overall, I give this book 5 stars as long as you're up for the challenge. While this book may not contain quite the volume of puzzles as some others, the harder puzzles can take well upwards of an hour to complete, so this book will keep you occupied for a long time.