The results are pretty good. From an LA Times article on the process:
Children with autism vary in their traits significantly: some can talk, while others can’t. Many of them are sensitive to noise. Some have trouble keeping eye contact, and many of them experience the world differently, so they’ll touch different objects to explore the sensation of texture. Perhaps because of this range, autism is also extremely controversial. While some organizations, such as Autism Speaks, consider autism a syndrome that calls for research to help mitigate its effects, others, such as the Autism Self-Advocacy Network, simply view autism as an alternative way of expressing oneself.
So by stepping into the fray, and by choosing the traits for one character to represent autism, Sesame Street risked facing backlash.
“Sesame can be a great convener of different interests,” Westin said. “We were able to bring people at opposite ends of the spectrum, pun intended, from Autism Speaks, to the Autism Self-Advocacy Network. Those groups see certain things differently, but what they had in common is they wanted to give families and children tools.” Both groups have released statements supporting the initiative...
Ultimately, after working with these groups and experts from such institutions as the Yale Child Study Center, they decided on these characteristics for Julia: She can talk. She cannot make extensive eye contact. And she flaps her arms when she gets excited. “We chose things we thought would be most helpful and most typical,” Westin said. On top of these markers of autism, Julia is very curious and smart.It's good to see that Sesame Street was willing to listen to actually autistic people and create a positive, realistic, autistic muppet.