Though I know this story wasn't written by original author, David Lagercrantz did a good job staying true to the original characters and their personalities, though at some times a few characters felt muted, compared to the the previous three books.
The story in general was fast paced and predictable, but not in a bad way. I had a suspicion early on about the the main protagonist and loved the "ah ha!" moment when it was confirmed. I especially enjoyed the way the characters back-filled the protagonist's history, which had been one of those minor questions that lingered after the third book.
Overall, this story book is an enjoyable, action-packed read; continues to provide insights into the unique character, Lisbeth Salander; and provides a setting for more books. Since this book is clearly not the end to Lisbeth Salander's story, I hope David Langercrantz will continue writing because I am looking forward to more of her story!