I'm completely biased when it comes to Stephanie's books. I like her writing style and her voice.
This is a post-apocalyptic motorcycle club (MC) new adult book. It doesn't feel as new adult (NA) as others in the genre do because the kids are forced to grow up quickly and deal with mature crap very early in life.
One thing that might throw people (it didn't me but I already said I'm biased) is where one character is mute (he signs all of his dialog) and there are some scenes written from his POV in first person. The scenes are short and are pulled out into their own named chapters (at least it should be that way in the final version) so you know you're getting that section from Mathias's POV.
You have the fighting and use of sex for power that you see in many of the post-apoc books. This book gives a different voice to those types of stories.