My younger sister is mentally handicapped (has learning difficulties in current parlance). She attended a Steiner school until she was 16 then moved into a hostel run by a local charity for adults with learning difficulties – she’s now 43.
The school was, in my memory and my parents’ opinion, excellent – really couldn’t fault it and it was absolutely the right place for her to be.
However I knew a few kids who went to a “normal” (for want of a better term) Steiner school and I’d have grave reservations. It seems to me to be a very hippy dippy let the kids learn if / when they want to sort of philosophy – which may and can work for some kids, but I don’t think I’d have sent mine to a Steiner school.