This is a very useful supplement for anyone running a Shadowlands or other combat-heavy scenario or campaign, as it provides numerous additional villains, opponents, and monsters (especially monsters). It will be less useful for more political (court based) campaigns, although there are a number of opponents that are designed to be used as infiltrators.
Like all of the AEG 4th Ed. L5R products published to date, this text has good production values and (color) illustrations, and is well-laid out and attractive to read.
Due to L5R using a non-standard system, the statistics and game mechanics given in this book will be difficult to translate for use in other settings, limiting its value for other game systems except as inspiration.
[4 of 5 Stars!]