If you're still looking for views on Nonsuch, am happy to provide some (though have posted with same views before.)
I have two DDs there, both quite different but both very happy.
Obviously Tiffins and Nonsuch are both very good schools and I do believe that your experience of either will be coloured by slightly more abstract things such as whether your child makes friends (and the "right" sort!), whether they get involved in extra curricular activities and how stressful their journey to school might be.
Obvious differences between the two
- Nonsuch has a catchment. Although we are OOC (though by a very small distance!), I actually like the fact that so many of my DDs friends live an easy drive/ bus ride away. Of course there are exceptions, but from my experience most of the girls live South Sutton/Cheam/Epsom/Ewell/W.Park/New Malden areas which are all very accessible.
- Nonsuch has fantastic grounds/sports facilities. Don't underestimate the luxury of this. I have commented in the past that Nonsuch don't make the most of their facilities, but I think this is changing. For example, the school has just asked parents whether they want their DDs to be involved in extra swimming lessons (free of charge) for those who don't swim well as the school believes this is an important life skill. They are also good at providing sporting opportunities for the not so sporty - DD1 currently doing pilates after school for example.
- Extra curricular - Nonsuch have the joint CCF with Sutton grammar. This is not everyone's cup of tea, but it is very popular. Unfortunately not all girls who want to be involved can be, but if you do get the chance its great. Also girls get the chance to ballgirl for Aegon tournament in the summer.
- Subject choices - this has already been commented on in relation to languages and a few others. Nonsuch also offers food technology - could be vital for some
To sum it up, I do think if you're fortunate enough to get either school, you are fantastically lucky! I know others have doubted the pastoral care at Nonsuch, but it's not something I've ever had to be concerned about (luckily!) I am aware of one incident where one of the younger pupils was feeling unhappy about a couple of incidents and the school dealt with it very quickly - though not necessarily in the way I would have
One thing I think both schools have in common is that they are not for the faint-hearted. Nonsuch is a pushy school and if your DD is not reaching their targets, you will be told about it! I personally like that and would rather know if something isn't working than it just being left to chance - I'm not sure that the girls feel the same way though
The pupils are tested frequently but I don't actually think that homework is too onerous - of course it may be that mine just do it on the bus or at lunchtime, but they still seem to have plenty of time to loll around doing nothing
One thing I don't agree with is the recent rise in the threshold for being able to stay on in sixth form. Although most of the girls are capable of this, there are always a few that don't make the cut and I think this is a shame.
Hope some of that helps!