Hello,
Well I can see your confusion, it seems like as a parent when you finally wrap your brain around something, someone else comes along and sees something else. Very confusing. I have a few questions and a few comments/thoughts.

First, what was his actual diagnosis? (Was it Aspergers? Was it PDD-NOS?) And who exactly gave this diagnosis? (was it a developmental pediatrician? psychiatrist? Primary care doctor, psychologist or social worker? and were they familiar with gifted children). You mentioned the eye contact, but does he have other social needs as well? What is your gut feeling? When you read up on Aspergers does that seem to fit for you?

You could be dealing with a gifted child that has sensory processing disorder. Or you could be dealing with a gifted child that has Aspergers. It's so hard to say as I don't really know him. Either way, whether he has something on the Autism spectrum or not, if he benefits from social skills then maybe he could receive some social skills training and working on helping him understand emotions and working on self-control and expression of feelings (geez...can you tell I am a social worker or what?). Possibly even someone at school or if you see more of a need someone outside of school. I agree with Grinity's point. I think that diagnosis can be helpful when it is used for obtaining future services and treatment. But it sounds like you have a good idea about what his needs are.

Hope that is somewhat helpful and I would love to hear more about DS8.