Probably like all books that are meant to be strange and mysterious, it's actually quite boring. The strangest books to me are those the authors meant to be understood. One example (for me) is Valis, by PK Dick.
It is so far from boring that I have agreements with myself about when and how I peruse it, to keep the pleasure and wonder of discovery going for as long as possible.
If you're not a fan of incredible, surreal, self-consistent art, then the Codex is not for you. The text is kinda hard to read. ;-)