I had a couple of outliers recently...full score 131 and 134 but one had a verbal 150 and one had a non-verbal 149. I'm anxious to interview them to see what I see. I like those high non-verbals, I call that the 'spook factor'--those innate abilities.
I think it depends on whether your child was prepped prior to the exam. Mercer Publishing offers practice tests for the CogAT exam at www.mercerpublishing.com/cogat.html These practice tests have only recently been made available and, I believe, they are shifting CogAT scores up (sometimes substantially) over those children who don't prep in advance and stick with the publisher's recommended advice of getting a good night's sleep and a healthy breakfast before the exam.