JCG posted:Helen, I think you answered your own question. It's about the school. The only thing I'd want to point out is that the UAA schools are pretty far flung, especially for a D3 conference. Lots of travel time. That can make a student's life a little more difficult.
Just to amplify what JCG posted: UAA conference is far flung, but the vast bulk of their conference games are played during spring break in Florida, where everyone in the conference, except Chicago, gathers for what amounts to a League Championship round robin. Wash U, Emory, and Case Western have dominated the past five years. The rest of each team's games are against more local competition with teams from OTHER conferences.
And as far as wanting a program that will challenge your son, as you already seem to have figured out, all four of the programs you listed in your OP take things very seriously.