This is such a neat concept for a character! They know stuff. And they can use it to practical effect. I seriously want to try this in a game!
It feels "bardy" in a way with the "Sage Advice" ability. I think those that like to play bards, could have fun with this too. This class allows you to fill the holes in your group.
This class is a goldmine for roleplaying. The absentminded professor, the awkward bookworm---you could have a ball with this one.