For math-y kids:
The pros of the WISCV:
1. It has a fluid reasoning index, separate from the visual spatial index, so you are not confounding spatial and abstract reasoning.
2. There is an ancillary scale, that the examiner can choose to derive from the figure weights and arithmetic subtests, called quantitative reasoning.
3. The new GAI is weighted with two verbal, two fluid reasoning, and only one visual spatial, which reduces the time and motor element in the GAI (previously block design was one-fourth of the GAI, now it's only one-fifth).
4. Verbal is now two-sevenths of the FSIQ, where it used to be three-tenths, so very slightly less weight in the FSIQ.
5. Picture concepts is not a core fluid reasoning subtest, which reduces the verbal content of fluid reasoning.
6. An ancillary nonverbal index can be derived.
7. The subtest ceiling is supposedly more robust than the old WISC.
8. The norms are as current as they can be.
9. Linked to KTEA-III achievement test & WIAT-III.
The cons of WISCV:
1. Examiners are not yet familiar with test administration and interpretation (though generally experienced evaluators should have no problem picking up the new subtests, especially if they have been giving the WPPSI-IV and WAIS-IV, as the new subtests on the WISC-V are largely variants of subtests from those two tests).
2. Extended norms have not yet been released, although supposedly, they are under development.
The pros of SBV:
1. Examiners are familiar with it and its clinical interpretation.
2. It has existing extended norms (but not all examiners have them).
3. It has also has a quantitative reasoning cluster.
4. Nonverbal quantitative reasoning can be calculated separate from verbal quantitative reasoning.
5. An overall nonverbal area score can be derived.
6. Linked to WJIII achievement.
The cons of SBV:
1. Decade-old norms.
2. Significant verbal content in the nonverbal cluster.
For what it's worth, personal preference: if I were your examiner, with the referral question and history you have posted, I would also want to try the WISCV on your ds.
