Vicious in three sittings. It was fast paced and entertaining, well worth the time spent reading it, but I'm not compelled to rave about it with quite as much enthusiasm as others have.
Victor and Eli were interesting nemeses, both ambitious assholes from the start, and when resurrected both lacking something that they might not really have had in the first place, that is empathy, kindness and any sense of healthy boundaries. We know from the start that this is a story about revenge as we are introduced to the characters (Victor in particular), and that these guys did some unethical science to get themselves some extra powers. In short, they became ExtraOrdinary (EO's for short). Ambition and a sort of competitive hunger drove them into this discovery, and testing it out on themselves without more than theories beforehand, and then it tore them apart. They came out on the other side of that experience different, with abilities they didn't have before and an apparent absence of kindness or empathy, that the lines of right and wrong had been erased.
I liked reading about the two men as they worked their way towards each other, trying to get the advantage, while unraveling their history and how they came to their abilities (and how they work). I was equally interested in the other EO's that showed up during the story. In the end though I was also irritated by Victor and Eli, their lack of insight into their own behaviors (it's the point, I know, but it was too much for my enjoyment, I know others think differently) and disregard for other people. I liked the sisters more, having a different kind of relationship, but similar, mirroring that of Victor and Eli to an extent (but then diverging on others). I love the depiction of close relationships that aren't healthy nor always mutually appreciated/equal (One sister trying very hard to be like the charismatic other, two roommates where one bests the other in certain ways etc). These things I like a lot.
That said the storytelling itself didn't always appeal to me, I felt no real engagement with the characters (good nor bad), I just didn't care, and while not telling everything is a great trick, I felt like I never got enough information to feel satisfied. I know there will be a sequel and I'll be reading it mostly to figure out the EO thing, and perhaps see if I can learn more about other aspects (like the police angle) etc. Not so much because I care what happens next, which would have been preferable. It is a decent story, and I liked more of it than I disliked.