I now have spoken to a number of existing Latymer parents, and feel reassured about my biggest specific concern - namely that the existence of 'too cool cliques' and related social pressures.
I'm also told that the school recognizes it needs greater participation in sports across the whole year group. I spoke to a parent who confirmed W4witches belief that this has already improved, and it is a declared aim of the newish head of sport.
Obviously, with a DS going to the school, I have not asked too deeply about girls sport... Venelope, is what you have read here put you off? I imagine that as the school has only been fully co-ed for a decade or so, the culture of girls sports at Latymer is not going to be as developed as it would be in an existing single gender school... but apparently they DO recognize it as a problem. If your daughter is sporty, as you say, then she will get into the A or B teams - it is more an issue with girls who are not sporty but would still benefit from sport in the D or E teams.
I wonder if there are any co'ed schools where boys and girls sports are truly given equal emphasis?
Looking at other schools fixtures/websites it seems that there is a similar dropoff in games played by teams lower than the C team wherever you go, and whether you are boy or girl. One thing I have been told - there are so many sports played at LU that your child will find one that they can participate in.
Academically, everything I have heard is hugely positive. Terrific and committed teachers. The school is apparently very good at getting kids to settle in at Year 7; it doesn't overload them with homework whilst still pushing forward with their learning.