Unfortunately, I think the series falls prey to the all-too-common business model of writing one book to see if there's interest and then following it up with a dozen books to pummel that interest into the ground.

If you look at it as a single, cohesive work, then you really get the "this could have used an editor" impression that there's simply too much and a lot could have be trimmed/excluded/modified to create a more streamlined narrative.

If you look at it as an episodic work (think Nancy Drew/Hardy Boys), then you've got too much backstory to learn. Imagine you're watching Friends and unable to understand what's going on because you skipped the entire season spent following Monica in cooking school.