I went to Bryanston. So did DH. I LOVED it. We hope DS will go there, and DD, if it's the right school for them.
Bryanston works well, IMO, for children with quite strong characters, because yes, while there is structure, one is responsible oneself for building it and maintaining it. As another poster mentioned, from an early age one has more 'free' periods than one would at other schools - for some, this works brilliantly. It's another hour in the art room/ practicing the violin/ time to learn one's lines for that terms play/ time to spend more time on one's English assignment/ whatever. For those who have a clear passion, and an idea as what they want to be doing, this structure works brilliantly - and there are few other school that are as encouraging of their pupils dreams, or who nurture them in such a way that they become reality. Just looking at my year: the girl who wanted to be an actress is, and she's relatively successful. Those who wanted to be artists are artists, and are making a living from it. The same with music - two of my year are world class musicians, with recording contracts (one of them only took one A Level, in order to free up more time for practice - a lot of schools would be worrying about league tables etc. and not allow this - not Bryanston.) In my twenties I looked around at my peers, and realised that a lot of them didn't have proper jobs - that they were still working in bars,and 'waiting for their film careers to kick in'. But, only a couple of years later, that Bryanston-taught persistence and belief in themselves has paid off. They're not working in bars anymore. They're doing what it was that they wanted to do.
However, there are others who Bryanston doesn't serve so well. I know that I would probably have got much better A Levels elsewhere, somewhere where I wasn't doing a different play every term, in choir, orchestra, writing for the school magazine etc. etc. For me it didn't matter - I'm still doing what I set out to do, and in fact talked my way into a much better university than my grades should have got me into - however, for others, I think that perhaps Bryanston didn't give them as much structure as they needed. They drifted, got by on doing the bare minimum, and some of them are still drifting now. But perhaps that happens at every school? Or perhaps other schools manage to get the necessary results out their pupils, before setting them free to drift (certainly, getting to university was in many ways a shock - there were all these people who had no concept of making themselves write essays just because they had to - without prep, or a parent or a teacher standing over them, they seemingly couldn't apply themselves.)
Awinawin mentions Bryanston being very 'monied', and Canford less so - I think to an extent this is true, Bryanston has always attracted a lot of liberal West London (Notting Hill) parents - but there are a lot of locals too - and everybody mixes properly.
Other things that I would mention in terms of recommending Bryanston: no bullying (but that comes with coeducation), the only girls in my year with eating disorders arrived with them in the sixth form (again, the lack of eating disorders is normal in coeducation), enormous freedom, beautiful grounds - there's more - much more - do feel free to private message me if you want to.
Canford is good too, incidentally. I've got friends who went there. it's just not as good as Bryanston. Obviously . . . .
DISCLAIMER: We're not sure how we're going to pay the school fees for DS or DD yet, so getting them there is a dream. But DS is 20 months, and DD is still in utero, so we have time . . .