It may depend on the specifics of the scores and what you're trying to do with them, but we were advised by the Gifted Development Center that the FSIQ on the WISC IV, in my DD7's case, just isn't accurate, and that the GAI should be used instead, because there is a 26-point difference between her scores on the highest and lowest sections of the test. In DD7's case, it could well mean the difference between getting into gifted programming and not getting into gifted programming, depending on the cutoff. We haven't tested this out since we have not used those scores to apply to anything yet, and probably won't (they also suggested that her scores will go up based on some stuff we're doing, e.g. vision therapy, and recommended testing again two years after the first test). So, I guess in our case, pretty much a 2E situation, we're putting a lot of weight on the GAI and none on the FS score.
At our post-test conference, the testers spoke about this GAI stuff more as official fact, but in the written report it seems more like an argument rather than a fact, which indicates to me that some controversy exists.
