I like the setting - that people are placed in one of four factions depending on their personality type - and the fact that main character Tris does not nearly fit into one particular faction, so is therefore considered to be 'divergent'. Tris is a likeable character and is very human, complete with flaws. There are several supporting characters, and the character interaction (particularly between Tris and Tobias) is great. The characters and the story are well written, but the ending of this book feels rather rushed, like the author ran out of words and had to squeeze the ending in. While the ending is exciting, I'd have liked a slower build up.
Summary - This is an interesting book with an exciting storyline, supported by lots of likeable characters. I found it hard to put down and I'm looking forward to starting book 2 tonight.