I have a like/hate relationship with this book and struggled with the rating. None of the good parts are quite good enough to inspire love, but there are parts that I liked. Roth writes a pretty good action set piece, and the main character undergoes a believable character arc. I also found the development of the book's central romance fairly believable. The pacing of that was good and didn't feel rushed or forced.
However, there was a lot about the book that I disliked. The core premise of the dystopian Chicago world of the story is so implausible that a friend had to talk me into finishing the book after I'd put it down with no intention of picking it up again. I had to not just stretch my willing suspension of disbelief, but lock it away in a Chinese puzzle box inside a dark cupboard inside a bank vault with an armed guard outside. I just don't buy that this society would ever come to be. People don't work the way they'd have to for this society to ever have functioned. So I basically had to shut off the part of my brain that kept saying, "Nope. Nope. Nope."
I was able to relax into the story for about the middle third [(even though the Dauntless training felt like it went on for way too long), but I started wanting to throw the book at the wall again when the book started its journey toward the climax and the anti-intellectual, anti-science themes took center stage. It pissed me off that the entire intellectual class — the class of scientists and academics and physicians — was portrayed as a group of power-hungry douchecanoes who just wanted to control everyone else (hide spoiler)]. I understand that the dystopia is about social engineering gone wrong, and I hope that Roth has some endgame in mind that turns what I've read so far on its head. I'm willing to pick up the next book on the strength of that hope that this is going somewhere, but this book on its own didn't do much to impress despite offering some moderate entertainment.