I have a child in year 7 at Holland Park. The children in the top stream are pushed and pushed. They are expected to be working at least at level 6 to stay in the top band and many are currently working at level 7 English and level 8 maths. An academic child could definitely flourish there. Remember there are no grammar schools round here to cream off the more clever and most parents do not even think about scholarships to private schools. The homework burden is heavy compared to other schools.
The initial streaming is done on the results of the test done in the the December before joining; however quite a few kids get moved up or down after the first term. It is important to note that they stay in the same class for everything; so if they are good at English and bad at maths they will not necessarily stay in the top set. The top 2 or 3 sets do Latin. They can choose either French or Spanish but those seem to be the only languages taught.
They have the same approach to GCSE's as many other schools - i.e. take some in year 9 or 10 and keep on resitting! I also dislike the fact that you cannot take the sciences as separate subjects. While saying that, a lad got in to do medicine at Cambridge last year with 4 A*s, so I don't think it necessarily holds you back.
The school has improved dramatically over the last few years, there are some disruptive kids or "chavs" as my kid calls them, but generally behavior in the school is OK. They are very strict on uniform and the teachers tend to shout a lot. There are a few things I don't like about the school. I feel there is a lot of favoritism and kids in the top class get picked for special stuff and others don't. I don't like the way that geography, history and RS are taught together as humanities. I also don't like the rewards system - Vivomiles - as again I think a lot are awarded on favoritism or natural ability and not hard work. I don't like the Head Teacher and the teachers have to work long hours. However the senior leadership team are very approachable and really do make an effort to try and sort out any problems. There are a lot of recent graduates among the teachers and they seem very good and committed. There are a couple of poor teachers but on the whole they seem excellent. There don't seem to be many school trips - in fact I don't think we have been offered any - but maybe there are further up the school.
There is currently building work at the school but the new building should be finished by Sept 2013 and the council is lavishing money on them.
I was at Oxford at the same time as Toby Young and would not send my kids to his school. I think getting into either of them depends to a large extent on where you live. To be honest if I had the choice I would still choose Holland Park because at least they have proven results.