Thanks- I think the CELF was one of the tests that he took. Verbal Comprehension was 15, Similarities and Vocabulary were both 18.
Interestingly, digit span on the WISC was a 13, but letter number sequencing was 18.
I think that DS reasons well (verbal and non-verbal reasoning) when the task is intellectual (esp. math or logic/analysis), but does not understand higher order social thinking or how to read social cues. It may impact some later writing and reading comprehension tasks (so I'm told). Right now, he's reading about two years above grade level.