If you value your games by their number of pages ignore my rating. From the starting 20 pages only about ten are the actual mechanics of the game. There are a few pages of setting information, and a lot of background to the decisions made in the game design.
If you want quality rather than quantity give it a read.
Great value if you want a quick workshop in game design, not so good if you like your games laid out on a plate.
At the end of the day it's John Wicks if you like his gaming philosophy you'll like ti, I doubt it will convert anyone though.