All of SFI's Tools are important.
The only thing is that you have to find for yourself which tool is best suits for you and really work well for you.
Every tool, co-exist with each other and compliment with each other.
Really hard to say that this one is better than the other one, for the reason that if you only have enough time to read and understand, take note my friend, understand, and then apply what you've learned, then success comes your way.
Onward and upward.
