What's odd about this feeling is that it's exactly the opposite of my initial sense of the work, where I was enthralled by the way the characters were drawn. It's absolutely incredible, the way Tolstoy seems to know exactly what it's like to be all these different people, and how skillfully he manages to convey it, sometimes with just a few small details. The plot sort of progresses through vignettes, and each of them is worthy of being a short story of its own; they're so vivid, and seem to index so much more than what they concretely describe.
Another thing I appreciated was how un-melodramatic it was, in contrast to what I was expecting. While it's ultimately a novel about passions, it allows the characters some margin of self-awareness, such that they're never on a complete tailspin - even when their actions are. I really, really valued that - the moments when they questioned their thoughts and feelings, even though their behavior was totally hostage to them. Thus, for instance, Levin finds himself jealous, and knows that he's being unreasonable, but just can't really help himself - which is EXACTLY what it's like to be jealous, unlike the usual portrayals where the person seems completely irrational and unaware of it.
The historico-political aspect of the novel was also fascinating, and really well drawn. It was the spiritual side I found rather less compelling, and it's kind of hard to say why. Unfortunately, that's what the culmination of the novel really hitched its wagon to, so the book ended on more of a whimper than I would have liked.
Still though, it's a great, great book.