I didn't hate it, but I'll admit I pretty much skimmed through it. There were interesting points amongst the pointless drivel and sudden random deaths of characters that had only just been introduced. I completely skipped all parts where there was kissing or lover's-arguments, aka half the entire book.
The underlying plot is still vaguely interesting - enough that I'll probably read the third when it comes out. Also the eventual films will hopefully cut to the chase in terms of plot, so it won't matter that I skipped a lot of it (don't feel that I missed much but still). Not badly written (apart from those cringe-inducing kissing scenes - eeergh) but probably best only for people who adored the first. I wasn't thrilled by it. The end revelation, though not too shocking, meant I'm curious to see what happens next though I will admit it started to make me think too much of City of Ember, which I feel carried out a similar idea in a more concisely planned and executed manner.