The Between is great. Every single part of the game adds to the story and deepends the characters. Even if you're powergaming, you have to powergame through the story. Each move, janus mask prompt, and dawn question (xp trigger) lead you deeper into story. Techniques like the Personal Quarters really force the group to listen to how each player introduces their character and builds the collaborative spirit from the very beginning. There is no fluff or wasted space.
The idea that you can only discuss characters' backstories when the game forces it is a really inspired choice and reinforces the cinematic feel that the author describes in the rulebook. We unveil relevant information only when it's relevant. As a player this also prevented me from feeling locked into a specific backstory for my character.
The book itself gives the keeper (GM) everything they need. The game itself is quite structured and the nature of the threats allow you to drop interesting and evocative details constantly. Everything is flexible enough that you can always incorporate something into the scene.
As with Brindlewood Bay the Answer a Question Move is absolutely magical. As a player and a Keeper it feels amazing to watch the group put all the pieces together and develop a story out of the various clues. The Between levels this up by creating more complex Threats where which question you answer can determine how a story goes and gives the players a lot of influence on what kind of story unfolds.
Edit: One thing I forgot to mention. Each threat is so flexible that you can play or run them multiple times and spoliers are essentially impossible. Each clue can come out in different ways and at different times based on how the group approaches each threat and which side charaters they engage with. As someone who GMs a lot, this is an enormous benefit.
[5 of 5 Stars!]