I have waited to test until my DC have needed it for school or a program. Our schools do quite a bit of testing on their own.
Neither of my children took the WPPSI, but I thought that it also lacked extended norms. I thought that at present, only WISC offered this. Actually, after the experience of having DD8 tested at school (and she hit ceilings on many of the tests other than WPPSI), I decided to wait until DS was 6 to have him tested so that he could take the WISC instead of the WPPSI (by the time we had a reason to test, he would have been an older WPPSI test taker). So the higher ceilings and extended norms would be another reason to wait.
Best wishes, Dubsyd!
