I wouldn't say that it's a great book - in that it's not terribly well written: not crappy, just a bit clunky.
It's a damn better book than any Dracula movie so far would suggest - and it has some seriously tense and scary passages. The best thing about it is the way the narrative and POV changes - makes it seem almost like a documentary in places.
Yes, I agree, Stoker was a master at creating suspenseful atmospheres, and I found the story structure very interesting, I have never seen it done nearly as well anywhere is, but it was good in that one can actually "see" as it were, the thoughts of some characters, see how their experiences are effecting them.