I'm with snowgirl. I think which to pay attention to is really determined by what you're trying to accomplish with the scores.
For example, I am home schooling my DS6 (aka darling son aged 6yo), so the fact that on the WISC, his processing speed score was over 40 points below his PRI and his working memory score was about 30 point below his PRI was significant info for me. Before he took the WISC, I thought he was just a dawdler, and I tended to get frustrated with him a lot. But now I know that he's not necessarily dawdling, and frustration probably isn't a useful response on my part. His average-range PS score is acting as a bottleneck (to use the term Grinity gave me) for what he can do. The GAI tells me what he would be capable of if his lower memory and speed scores weren't getting in his way.
As a result, I have some useful info about how he works, and I can adjust the type of work I do with him so that I'm not always nagging him to hurry up. That's helpful to me!
So I think ALL the results *can* be useful, depending on what you're doing with them.
Now, if you're just asking "Will the school accept the GAI instead of the FS for entrance into a GT program?", that I don't know. You'd probably have to check with the school.
Are we getting at what you want to know here?
If not, maybe more specifics about your particular situation would be useful?
K-
