i don't know about the steiner methods of education but i'd have to say that the one adult i know who was steiner educated (primary and secondary) is self-absorbed to an astonishing degree and finds it very difficult to cope with dissent. In the sense that everything she says is right, at any rate...
and i see a couple of steiner kids at childrens' parties i go to, they don't seem to intergate well and one in particular always has to be taken home...
not a brilliant survey, given that it has a sample of three, but i would worry about them when they get to secondary school. i have heard that the brother of one of the younger children found 'mainstream' education very difficult indeed and became very closed-off and resentful of his parents. don't know him, though, so can't say.
it does sound lovely, all that self-expression, but i just think that sometimes children do need to learn that the world isn't necessarily interested in their opinions. tough lesson, but since i don't think the world is going to change to fit them, it might be one worth learning.