My DDs were reading very early - including the one who went to a Steiner school when small - she just read at home and enjoyed the freedom of what went on at school - the reverse of normal! - which was fine. Children who are not as bright as she was benefited from not being pressured into learning to read before they were ready.
Steiner's theories were of their time politically - not great - but he had some good ideas but education. As I say - I ignored all the "woo" and other stuff and looked at what the benefits were for my children. Steiner schools are of course very inclusive now.
GSM - I think the whole point is to have "totally different learning experiences"! There were never any problems with my 2 DDs who went to the Steiner school fitting in with others of their age, whom they met through Brownies and other activities - it was all fine.
Every school is different in terms of the quality of Steiner education they provide - good ones and bad ones, just as in the state system. I am always slightly puzzled as to how the local Steiner school always gets an "Outstanding" as clearly the targets in the early stages are not met (deliberately of course). OfSted are clearly applying different rules for them and recognizing that it is a different system. I always feel a bit pissed off that the state primary where I am C of G is not afforded the same parameters and allowed to ease children into their learning more gently.
I am very much of the view that the rigidity of our state education system and the strait-jacket of the national curriculum has been to the detriment of education in the UK - particularly for the slower learners who just switch off and often become disruptive, and of the teachers whose freedom to use their professional judgement is curtailed.