It left me underwhelmed. I understand the basic concept - that our narrator lacks empathy - and it is an interesting literary exercise. It bothered me, however, that it is implied that the narrator may/would have been acquitted for the murder of the arab if he followed the (often nonsensical) rules of society.
It struck me that our narrator committed a impulsive act - and was punished accordingly - because he couldn't control his anger. I don't see how/why the narrator's lack of empathy is of import.
I must be missing something. But what?