The manga seems pretty boring to me. Compared to the anime (which looks pretty ridiculous) it's probably a masterpiece of writing but from what I've read (2 - 3 volumes) the arcs really aren't that special. There's no point to reading the story because you know the story isn't going to diverse from the boring status quo to begin with. That's what I don't like harem anime or manga of either kind, shōjo, seinen, etc.
Believe it or not, they do quite depart from the harem crap into more interesting things further on.
Such as Tsukune becoming a ghoul and controlling his demonic side and stuff.
The manga takes a little while to fully get it's plotline under way.
They play around various times with Tsukune getting killed in pretty violent situations, and Moka reviving him by injecting him with her vampire blood, which heals him and turns him into a badass vampire for a short while until the blood's power wears out. So the situations go from Moka having to save everyone, to Moka having to save everyone then turning Tsukune into a temporary vampire to kick the crud out of the enemy of the chapter, and eventually before that gets too old, Tsukune finally goes over the edge and becomes a berserk vampire/human hybrid monster with an insatiable killing instinct. So then they lock that up with something similar to Moka's rosary, and he gets trained how to USE those powers without being consumed by them.
The art style undergoes quite the shift from the beginning to the more recent chapters too. I mean really. it looked pretty cartoony and simple at first. Now? well now it kinda resembles deathnote a slight bit.