People have suspected that I have Asperger syndrome. I did visit a psychiatrist once as a teenager. I don't know if he ever gave me a formal diagnosis, and besides, there are certain aspects of the syndrome that don't quite fit me. (I've still lost opportunities over it; once was told I'd never be a leader because I was too awkward on stage and since he heard I had Asperger's he assumed I'd never be able to get it. After a few weeks, he partially backed down.)
The autism spectrum is very broad. It'd be difficult to portray a character with a "typical" case of autism.
My son who is now 15 has Aspergers which they now call Autism Spectrum Disorder. You are correct it does effect kids in different ways, but in almost all cases they appear awkward to thier classmates, and have few friends outside of maybe a few like them they hang out with at lunch. It was heartbreaking in elementary school when he would pass out a classroom full of Birthday party invites and nobody comes. At Christmas when other kids ask Santa for a new X-box, he's asking for a fire alarm pull station and a specific model of one and he knows all the models.
I think its a good thing to introduce kids early to this dissorder, so maybe they can understand the boy or girl sitting next to them, and relate better.
And I'm pleased to see the conversation here on TBR is staying intellegent. The same topic posted on TOS would get ugly fast, someone denying the condition exist or some other stupid insulting comment.