I think that 11 yrs is too late for team games. I went to a lovely little village school, which I adored, but we didn't have enough for team games and I felt that everyone else had too much of a start when I got to secondary. I think it might have been OK if I was especially talented, but I wasn't.
I think there is a bit of a danger in reading about all the success stories in autonomous education and it gives the illusion that anyone can do it. We never hear about the failures.I think that everyone knows a success. My SIL had a boy in her EO group who did nothing-got up late, watched TV etc, couldn't read, no motivation but suddenly aged 15yrs he got his act together and ended up going to Cambridge at 18yrs. However he must have had an IQ well above average to start with-you have to bear in mind that most HEers have average DCs, if they all had IQs of 130 that would be the new average. My SIL equally knows those who she feels will be utterly unemployable (like the innercity kids failed by the system, they have been failed at home).
I would think that the main problem with autonomous education is that you don't know what you want to learn in the first place. It is like giving a DC a choice of food and saying 'you can have whatever you like', they choose from what they have already experienced and everyone else has much more interesting dishes and they then get upset and say 'why didn't you tell me-I would rather have had what x had'.
I can think of quite a few subjects that have seemed as dull as ditchwater in advance, but have turned out to be fascinating.
I always like reading seekers posts on HE, I think she is one of the few people who can give an unbiased account from both sides. She has been HEd, enjoyed it, doesn't regret it, but because she doesn't stick to 'the party line'and can point out negatives and sends her own DCs to school, people don't want to listen and I have been surprised at how unpleasant people can be. There was one thread recently where she had to give up posting(unless she just went on holiday and wasn't around).
Not everyone supplies a positive experience of HE for their DCs just because they are a parent, and want to-they may be hopeless. The DC who gets up late,watches TV , plays computer games and has no motivation may never change.
The social side of HE wouldn't worry me because I think that there is a sizeable HE community-however there is a thread running at the moment where 2 people are finding their DC very isolated and the HE groups quite cliquey-so perhaps that varies according to area and isn't such a rosy picture everywhere.