I agree with you that it's ultimately about the characters, but the characters aren't written the same as in the original three books. How can that be considered good, or good writing?
Bella, Edward, Charlie, Renee and Carlisle all acted different from how their characters were originally written.
Bella had decided, at the end of Eclipse, that she would never again distress Edward over Jacob again. And yet what does she do in this book? She wants Jacob to stay by her side, ignoring how that makes Edward feel, or how terrified he is for her. That's not the Bella from the first books.
Edward is concerned not only for Bella's physical well being, but for her soul as well. That's why he insisted on marriage before sex. If this is his character, why would he offer her to Jacob to commit adultery, and doom her to sin? That's not the Edward from the first books.
Charlie is a doting father and a cop, so is suspicious by profession. Remember how he disabled Bella's truck when he even suspected she might sneak out? Renee got hysterical when Bella was missed by the van of destiny, flew from Florida when Bella landed in the hospital. They would BOTH have been on Carlisle's doorstep demanding to know what happened to their daughter. Charlie definitely would not have ignored the fact that Bella looks different and popped out a toddler.
And Carlisle had been a doctor since medicine was invented. It's his life's passion to ease human suffering. He's able to withstand his thirst as a newborn for months at a time, but he can't hold off on a hunting trip when his patient is so close to her time? And on top of that, he has absolutely no medical knowledge. If the mother drinks blood, it doesn't go to the fetus - it gets digested. If they give her an IV, it still goes to the mother. Further, they were feeding the baby regular food later, so it was not necessary to feed it blood. Just more author-forced drama.
Meyer has said that her books are character driven. How is this book supposed to follow the others when the characters are written so far from the original? How is that supposed to be good?