My daughter is at bullers wood. My sons will most likely go to Ravensbourne. They would both prefer mixed (and it would suit them), it's walkable, and I really liked it at the open day.
I went there when was seen as the poor relation school - heaps of upheaval as it merged and so on. Still went to RG university and still think I got a good education there, despite the problems it was going through when I was there. Now it's much more popular, and has a more varied intake. I think my sons will be happy there. The Ravenswood catchment has recently become larger, after a rather tricky time there involving poor ofsted and some exams shenanigans. But I have friends with children there who seem happy and to be doing well.
I have registered an interest in the BWSB but still not sure - would prefer mixed, am slightly concerned that they won't get planning permission, not convinced that will be good for the girls school to lose some of their grounds, and my eldest ds would be in the second intake, so could all still be rather chaotic, with only one year group of older children as older peers.
I think that if I was starting in bromley with a blank slate, live anywhere status, I'd aim for hayes. Lots of quite large good primaries and a very good mixed secondary (hayes - only about a mile catchment). That said, I do think that we're pretty fortunate in bromley to still have in general rather good secondary schools, and not to have significant top-slicing to grammars.