All three lack good story writing. All three obviously missed good editing. But the three distinctly different styles of illustrations are worth the look. I'm listing them by illustrator.
The Hungry Ghosts pictures by Geraldo Valerio 2009
How the Nobble was Finally Found pictures by Stephen Gammell 2009
Leon and the Place Between pictures by Grahame Baker-Smith
The artwork in each book is well worth your time.
The Hungry Ghosts illustrations are done in acrylic paint on watercolor paper, lots of blues on every page. Nobble illustrator Gammell is the same artist who did Old Black Fly (1991 - Jim Aylesworth). Gammell created the handlettering seen in the text of Nobble. Baker-Smith used digital montage for the pictures in Leon. It has a 3-D effect that draws your vision into the busy setting. Of the three, Leon has a story that at least flows and is not a bad read.