My DS has a similar profile (see 9/22 post)and we are scheduled for the interview portion of the neuropsychological testing next week. I am in no way an expert in any of this, but if I was offered a chance to go back five years to have the testing done, I would jump at it...more time for any suggested therapies, instruction etc... and, to have more concrete answers for random teachers, substitute teachers or middle school peers who can question the differences.
I have found thi link helpful recently when questioning our decision to put our sensitive middle schooler through more testing.
http://www.sengifted.org/articles_counseling/Webb_GiftedAndLDANeuropsychologistsPerspective.shtml