It depends in my opinion. I have one of each. difficult child is diagnosed with a school based anxiety disorder under the ED classification. Oldest boy is OHI. At one point, they wanted to call him Asperger's. I do not think he is (long story) but in order to get him into the placement I wanted him in, it was the best diagnosis. But I insisted that we keep OHI as the formal classification.
I wish I could change difficult child's classification but it's ED or nothing since he has no LDs (he is in HS level math and science in middle school) other than expressive writing disorder (which is a fancy way of saying he refuses to write anything other than the facts). ED makes the school look at them like behavior problems even when they aren't. The Aspie diagnosis makes the school cut them more slack, like they can't control the way they are. ED kids often can't either but like ADHD kids are expected to.
IF your son is Aspie, I would go for that one and then make sure that in the narrative portion of the IEP, all of his behavioral issues are discussed and related to the Asperger's so that if he does act out, you will easily be able to say that it's a manifestation of his disability.