@WorriedMomSE We've ended up putting DS in for Crown Woods mainstream in the end. We don't know yet if he's got a place there though (LA said we'd find out in February).
We visited John Roan. DSP lead seemed lovely, but kept pushing us toward Thomas Tallis, which felt very odd. "Have you seen TT? You should look at TT. My kids went to TT, we loved it..." She also very quickly changed the subject when we brought up A level options. I did see something on the always-reliable-Facebook that a number of the SEN staff had their jobs cut shortly after we visited. If true, this may have been a factor in her attitude.
We visited TT on both an open evening and an open morning. We didn't warm to it. SEN staff (not sure who she was, but not DSP lead) that we spoke to was lovely, but the school was noisy and she pretty much shrugged and "there's nothing we can do about it". Which is true, in that the buildings aren't set up to absorb sound, but it didn't feel great for DS. He did love the science experiments going on in the classroom during the open evening though! (Fire!)
We visited Crown Woods as it's the closest to us and were very pleasantly surprised. Open evening was crowded and noisy and DS was quite overwhelmed. We talked to the SENCO for quite awhile and she was great and everything she said sounded very reassuring. We visited an English classroom and one of the teachers clocked us as we came in, saw DS was stressed, immediately offered to turn off the music, looked at DS again, and took us into the next room which was quiet and empty and chatted through everything with us.
We visited again on an open morning and started off on a big group tour. Within 5 minutes we knew that wasn't going to work, so DH asked the Head if we could have a tour on our own. He was lovely and immediately got two girls to show us around. Both had some SN (dyslexia and stutter, I think) who both were enthusiastic about everything, including SEN provision.
Crown Woods has a DSP space, but isn't quite right for DS (he would not get a place there), but SENCO said the facilities (sensory room, etc) would be available to him if necessary. He's spending most of his time now in mainstream with support, so we are hopeful that he can cope with support at Crown Woods. We put down TT DSP as our second choice, but I don't think we'll get it, which will leave us at TT mainstream, which I think will be a disaster.
We never did get around to looking at Woolwich Poly as it's really too far - it would have been 1.5hours commute each way. Halley Academy we didn't look at because it only aims for 50% reintegration into mainstream and that felt like a step back for DS.