I agree. I agree with both the reviews that give it a 2 and the reviews that give it a 9, as I hated the manhwa as much as I loved it. Therefore, I have never ever had such time reviewing a manga/manhwa/manhua, and I would suggest that you stop reading the reviews even my one and just read it because it's worth it.
If you are curious though bare with me while I explain what is so good and bad with this manhwa.

The best thing about the manga are the characters combined with good storytelling. It is rare to have such 3D in depth characters, and this is the reason you stop perceiving them just as characters, but begin to really invest in their fates. This is also the reason why the drama works, and when I say drama I mean real drama. The drama you feel deep inside your heart as if it was you that was in the story and not the MC. The pain, the happiness, all of it all real.

Now for the bad side... How should I put it? It left too much unanswered, but in a bad way. It got us to invest too much in a side character, just so that the story could throw him out later. Some issues remained unsolved, and all the build up just lead to nothing. On the bright side; however, this does not include the characters. All of their actions were consistent and even when they left you wondering why the hell they did something, you could easily understand their viewpoint.

Just a side note, when I say that you should read it for the characters, I am not saying they are likable. Actually most of them are quiet the opposite, and that is what makes them interesting. They are human beings (or vampires) that have emotions, desires, flaws, and their quirks (or are outright crazy - don't say I didn't warn you).

Anyways, please read it. It is something else and this is hard to find these days :).