Danov is one of the very rare people, who won enlightenment. Many now make a living, by pretending to be enlightened teachers, but he was amongst the very few authentic ones (who of course do not take money from people in return for their help). So no doubt whatever he had to say, it's good that people publish.
Unfortunately, this book needs more editing, as some of the text is very confusing (seems like mistakes with both the English grammar and the very meaning of what Danov is saying, as expressed by the translation. It is probably a translation, as Danov lectured in the Bulgarian language - not English).
I heard that Danov himself did not write books. So this is based on things that his disciples wrote down, based on his talks? Well, maybe they didn't understand fully what they were being told. After all, most of what he experianced, they have not. Even Zen books by D.T.Suzuki did not give me this impression, of such confusing texts. My English is probably far from perfect, but I think such important material as in this book, deserves a new, improved edition.