I'm a sci-fi writer and reader, although, let's be honest - I'll read just about anything that moves me, regardless of the genre.
I knew nothing about Divergent before reading it, other than it was Hunger Game-esq. That being said, I'm going to say right off the bat that Hunger Games is way better than Divergent, but Divergent gets four stars because I read it in a matter of hours, so good job Roth, you kept me entertained.
I'm going to make a comparison to Hunger Games, so bear with me here. I'm not going to get too bogged down in Divergent's plot. It takes place in future Chicago. When a kid turns 16 they pick a faction to become a part of, and then they are subjected to a try out where they have to prove they actually do belong in that faction. The main character, Beatrice choose the faction Dauntless, and it is at this point I started to have problems with the book.
In Hunger Games, I never really had that much of an issue suspending my disbelief. The idea of a gladiatorial arena for killing kids wasn't as hard to wrap my mind around as the idea that there is an entire faction of people who are constantly taking risks such as, but not limited to, always jumping from train cars and then breaking into a dead run upon landing.
I know what you're thinking, that's what bothered you? Yes. Have you ever jumped from a moving vehicle and tried to stand, let alone run? Unless, in the future when America falls apart, people magically evolve stronger ankles, everyone in Dauntless should have major ankle injuries. No one in that faction should be able to walk. Seriously. You jump from something moving enough times, and you know what I'm talking about. The numbers of injury opportunities vs. injuries accrued would be much higher than Roth suggests.
This whole ankle thing is just one of many little details that really made me have a hard time believing the story. That and I felt like the first part of the book didn't really go anywhere. I just kept waiting for whatever needed to happen to happen. It isn't to say that nothing happened, I just felt like the book was wandering from its main point - that of Divergence.
I haven't picked up the second book, yet. I probably will, but in the end, Divergent wasn't as crisp and focused as the Hunger Games. There was a lot of risky risk taking that as someone who works in a field that constantly requires risk management, I knew that such stupid risks wouldn't really be worth taking because you'd thin down your numbers so fast that you'd have an entire faction of injured people.
If you're not someone to get bogged down in physics or the reality of what Roth is saying, you will probably greatly enjoy this book. If you are someone who might have the same issues as I did, just know this book probably won't be your favorite, but you might still like it.