I found this very helpful to parents:
http://www.fcag.org/documents/summerguides/summerguide2009.pdf

The SCAT isn’t used for much.  I think it’s considered rather coachable.  I’ve had my children take it, and qualify for those programs, but I wouldn’t assume anyone would put a lot of weight on it other than for CTY.  It is a single data point.
 For GT identification in school, a more acceptable and usual [...]