The book works if you heavily modify the author's plan. First, the pros:
1. He gives a good outline of how many chin ups you should be doing each work out. I agree with him on this point.
The Cons:
1. He claims that his workout trains the delts and triceps as well. It does not. Chin ups stretch the delts, which is nice, but nothing replaces old-fashioned shoulder presses.
2. He has you doing chin ups every other day. Besides the fact that few people have the aerobic ability to recover that quickly, it's also dangerous muscle-wise. By the end of his phase, you are doing 40-75 chin ups a workout. Your body needs rest.
3. I couldn't make gains going on his plan. I had to modify it. I go every three days, which eventually sets me a few weeks behind. That's fine. Progress is better. Better modify it: once you get past week five, don't immediately go to week six. Do a different type of regime (kettlebells, weighted chin ups), then go to week six. Or something like that.
Conclusion:
His regimen for how many chin ups you should do each workout is good. Everything else is either unworkable or dangerous.