On the plus side the school has fantastic pastoral care, the children are listened too, treated as individuals and there is mutual respect between adults and children. The teachers are approachable and open to working with parents.There is a good positive community feel and I find the parents in general positive and supportive of the school.
and
My son is happy at his school and relatively settled.
vs
I had a tour of it along with other prospective parents and it seemed efficient and well run. It has an excellent Ofsted report. It did however seem regimented and wall displays of current themes etc in the corridors looked like they had been done with a huge amount of adult input. The school was polished and spic and span but did not have the more child friendly feel that my son's present school has.
I am however thinking that moving him to the other school would almost certainly be beneficial academically.
... would make me stay with your current school.
You do know that the greatest influence on academic achievement comes from parental engagement (NOT school choice)? Your DS is lucky enough to have that, loads of it, whatever school he goes to.
Generally, children learn better when they are "happy and settled". For the sake of his academic achievement, I would leave him at his current school, but try to get to the bottom of his difficulties and provide him with targeted support. You'd have to do that anyway, wether you change school or not. And doing it at a school where the teachers are open to engage with you, and pastoral support is great, will be easier than at a school that is overly focused on results (which, IME, 'outstanding' schools tend to be, because they are well aware that they are very likely to lose their 'outstanding' if their results slip), and where you don't know the people well yet.
If you find your current school being unhelpful at getting to the bottom of your DS' issues, or unwilling to put any identified extra support into place, THEN is the time to look at other schools. Before you move, you can then talk to the SENCO of the prospective schools and find out if, given your child's particular context, they would be able to support him appropriately.