I don't see how this method of note taking is better than just writing note linearly. Sure, it is good if you want to recall information for writing a book, but it doesn't seem like it would actually increase your retention and improve your ability to apply things that you have learned. If anything it would make you less efficient at learning because you have to maintain this note structure.

It seems like it's only good for summarizing or collecting information for repackaging and publishing. Maybe that is all it's purporting to be, though.