My take on schools is that it is not just all about math levels... but the whole picture. I want to have my child engaged during the hours in school - with his peers and his learning environment. We already got a taste at 3 what it is like when he is not engaged, and we simply don't have the bandwidth to do afterschooling to make up for what he was frustrated over (or angry about not getting).
Everyone will have different options and opinions on what works for their family, but for me, having my child lashing out at home or spending hours whittling the time away until pickup is not worth dealing with mediocre school situation. And - for DS, having a peer group he has now has made it completely worth everything we have put in so far ... and he tends to be a well-liked child especially with the opposite gender, so it was not that no one would play with him, but rather that he felt out of sync with the kids at his old school. At his age, it is not purely about academics, but having a group he loves being with, and a place that emphasis not just academics but social and emotional development.
