I watched this after watching Ruiz's version to get a better handle on the story. While there are many similarities, this version is much more straightforward than Ruiz's. That doesn't necessarily mean that it all makes sense. Both presuppose a familiarity with the text, which I think is a bit of a weakness. Add in the fact that the book caused suicides, this is a very tricky proposition.
Agreed, the book is a horror phantasm of E.A. Poe-ish lineage, one might even feel the cold pall of Baudelaire. It is the Symbolist world of an Iranian exile living in a European City, constantly estranged, rotting, yet never able to leave his original Persian culture, it's history, philosophy, deadened by political strife and otherworldly despair. Find the book, the film is a hollow husk of its actual potency.