I skimmed through some of the other reviews of this book. I can see why people might not be happy with the author's interpretation of an "Asperger's syndrome" teenager, but would remind them that Marcelo never says that's what he has. It's just something he uses to explain himself to others. Maybe it's the author's hedge for when Marcelo isn't what people might expect. 
 I thought this was a lovely book. It took me a while to get into it because the television was on and I was distracted, but I didn't go to sleep until I was finished with it. So, you can read it in one dedicated evening. And it's definitely one book I'd recommend. 
 Marcelo is an innocent thrown into the "real world" by his father who doesn't want to believe there is anything wrong with his son, but at the same time underestimates his child. Marcelo is faced with doing the right thing, even though it might cost him what he thinks he wants most. 
 I enjoyed Marcelo's discussions with the rabbi. You can see he has a grasp of some very difficult concepts of good and evil, right and wrong, even though he has trouble reading people's expressions or intentions. 
 I believe the book cover compares Marcelo in the Real World with The Curious Incident of the Dog in the Nighttime, but for feel . . . and I have nothing to back this up intellectually . . . it reminds me of The Catcher in the Rye.