I agree about the problem with the EXIQ norming sample. It seems odd to not have included any kids over 150 full score. I think the extended score just serves to further muddy the waters where IQ scores are concerned. And I do have 2 kids with extended scores calculated higher than the sample group, so this is not sour grapes.
I've always liked the snapshot view of testing. On a good day, I might appear at my personal best in all ways- hair neatly styled, face looking its best, clothes just the right color and shape to accentuate the positive and distract from the negative. On a bad day, my hair might be a disaster, I might have obvious blemishes, dark circles under my eyes, and my clothes could be a complete fashion-don't. Most days, however, are somewhere in the middle. Likewise, testing should not indelibly stamp a person with X IQ. To me, scores should be a starting point for learning more about a child, and not a final word.