If just compare primary school to primary school, I will vote SFA because it can help your child to build a better foundation especially in languages (my own opinion only). My friend's son studying in SFA and can speak fluent English and good Mandarin. This is fact and that's why I am impressed!!
To me, language is VERY important and that's why I rank SFA higher.
Then no matter which secondary school or even university your child study, it should not have big problem...
However, to compare all factors in a long run, you are the only one to make decision as you know the best of your child and your own situation like having two childs etc. Don't too worry, both schools are good too!