Maybe a 3.5 rating. 
 I found that I disagreed with some of the choices that Tris made, and that took some of the joy out of the reading. Without a doubt my favourite character was Tobias. He was just such a great guy and (view spoiler)[(amazing for ever forgiving Tris for lying to him SO MANY TIMES). Of course it all kind-of worked out in the end, but still. Tobias' love for Tris was tested and went through the fire in this book and it came out strong in the end. (Much to my slight unbelief). (hide spoiler)] I confess was a bit angry with Tris; she has a tendency to lie to the people she loves quite easily. There also seemed to be some inconsistencies and some of the things that just "happened" I wasn't quite able to swallow. It seemed less realistic than Divergent and that also disappointed me a tad. 
 Veronica's writing though is still as strong as ever and she doles out the action with every page you turn! I'll be getting the next book when it comes out!