I wonder how the critical reception to The Pale King will evolve over time. In my opinion it's been a bit over-esteemed by fans of DFWs work. It really does feel incomplete, and not just in a Brothers Karamazov sort of way. It lacks a center of gravity, and I never really felt a strong connection with any of the characters. By the end of Infinite Jest the book had become something greater than the sum of its parts, and I didn't really feel the same thing happening with The Pale King.
The only part of the book that I feel comes close to the greatness of Infinite Jest is the 100-page 'As the world turns' chapter. But then, I don't think that chapter necessarily benefits from being a part of the book, and could just as easily have been published as a stand-alone piece.