I agree with 'Neato. Testing helped us a lot, even though the school did very little with it and we ultimately pulled him out for homeschooling.

YMMV, of course, but especially if you have a child who hides his abilities to fit in or who doesn't necessarily look like people/you think a HG+ child is going to look (GT denial, anyone?), then seeing the test scores can really help you to recognize your child for who he is and do a better job of meeting his needs, whtever they might be.