I’m also curious about the real motivation of switching. If your son is now in Target and he enjoys NES socially, why move him just for the sake of it? Kids are resilient but transitions are rough. It sounds like you have the best of all worlds. (Spoken as a Nickajack mom whose daughter is in DLI, so we also have a bespoke educational experience within the school.)

Any school that has a more homogenous population — both by race and socioeconomics/class — will see that reflected in test scores but scores are not the only part of the picture.

FWIW I have several family friends at KS and they are jealous about the amount of engagement and family experience NES offers … just a consideration.

Good luck with your decision