I've only read Harry Potter, and no Twilight (although I have seen the film), but I can say my initial interest in Harry Potter probably came from beginning the first book in sixth grade. Even though I was well into college by the time the last one came out, and probably outside of the target age range, I'd basically grown up with the characters.Maybe I personally would have adapted better to Twilight if I'd started reading as a pre-teen; but as it is, it just rubs me the wrong way.