We are a couple of years ahead of you as ds2 now in y9 bit I was petrified of the whole secondary transition process and tbh couldn't see how it could possibly work ...
However it's been so much less stressful than I could have ever imagined. Ds is in the 'grammar' stream of our local school and thankfully for him the streaming is based primarily on maths ability - his class is chock-full of other bright, geeky boys many of whom occupy the blurred space between ASD and NT so although he is less socially aware than the other boys he doesn't stand out nearly as much as if feared. There appears to be very little homework and certainly no projects (phew). We'd stopped song homework in y5 as I told the primary school that it simply wasn't worth the hours of meltdowns which were affecting the whole family and if they wanted to tackle the issue at school they were more than welcome to do so.
Homework in secondary appears to be mostly acceptable and he doesn't get stuff every night (double phew) - his lsa is now very on the ball about checking that he's understood the h/w set and has written it down correctly - we had a memorable instance in y7 where the only thing he'd put down for his English homework was 'do thing' - we never found out what 'thing' was 
I would second moose's suggestion of getting him typing - that has transformed ds's output both at schol and home - he has dyspraxia as well so his handwriting is slow, painful and virtually illegible. He now uses a laptop for all homework and extended writing tasks
He is miles happier in secondary than he was in primary - his days are much more predictable and they don't have dressing-up days or themed cross-curriculum days so far fewer unpleasant surprises as far as he's concerned. We had several instances of school refusal in y6 but so far that's not happened at all
Definitely talk to the senco at whichever school he gets offered - we were able to take ds on for a couple of extra visits in the summer term which helped the school become more familiar - good luck