First off, let me say this, if I haven't: I'm a huge fan of Edgar Allan Poe. His stories and poems woke my creativity; made me appreciate the macabre and morbidity that transcended what people in his time grew accustomed to--Austen, Dickens, etc. Without him, I think we wouldn't have people like Tim Burton, Bram Stoker, Marilyn Manson, Neil Gaiman. He was a man so underappreciated, so misunderstood and so before his time.
With that said, with the added Gris Grimly illustrations seemed to deepen the creep factor. I, also, took Neil Gaiman's advice and read Poe out loud, which made me firmly grasp his language, descriptions, imagery and metaphors--which there is a lot of, in his stories. I always try to read at least one Poe story this time of year; my favorite one from this collection is probably Black Cat, with Masque of the Red Death, a close second.