I'm in the love camp as well. I thought the animation was very inventive and especially refreshing considering the rise of Pixar and all of its clones that have dominated animated films for a little while. The conflict of these rather forgotten individuals that don't quite fit in to the structure of our world is treated with great dignity and humor. One of my favorite recent books, Jon Ronson's "The Psychopath Test", does bring into question how mental illness, or "craziness", can be exploited for our entertainment, but I think Adam Eliot crafts this one with enough care to avoid such exploitation.
The only issue I have with the film is the overkill of Perpetuum Mobile. It's a powerful song, but I think it's rather obvious. I also think it might take just a bit away from some of the later powerful moments of the film that would have benefited from a cagier utilization of music.