Writing this almost 9 months later. I almost re-listened to this earlier this spring, but then realized I had already done so. Probably during the drive to/from my team retreat in October.
It was sort of weird; not really following the first 3 novels at all. The main character eventually DID show up, but only in the 2nd half. The setting was a weird "popularity-based" society where your score determined everything from where you lived to what you could do. Pretty typical, but I don't think it was too unenjoyable either.
I think there was also some sort of worldwide conspiracy they tried to uncover, only to realize that it was an attempt to save the world, and our main characters were going to be a part of it. Sort of nice to end the series on a positive note.