This is a difficult one to review. On the one hand, it's a short book that delivers on what it promises. You will likely get good ideas / insights from this one for momentum style investing / trading.
On the other hand, it is difficult to take the performance claims from the beginning of this book seriously. If you can really compound at 200% a year (Buffett clocks in at a long-term average of ~20% for reference), then why would you also have a multi-thousand dollar a year trading course? Perhaps books are written altruistically to spread knowledge, but paying so much for trading doesn't fit with someone who can make those type of returns, in my opinion. The investing contests that back up the performance claims also looks off, again, in my opinion only.
So with the above said, does that fully invalidate everything in the book? I don't think it does, but it definitely casts some doubt. Momentum investing works, that has been proven by many studies. But making 100%+ returns most years with (from memory) only 1 down quarter seems to me to be beyond the realm of what's possible.