My comment is KCS is better, as in future Putonghua is a trend, so better familiar and equip with this language at your child's earliest age is better. In terms academic, maybe KV is more harder as it has no education voucher so it could be harder (more writing etc.) and better connection with strict Primiary school, but in fact, it depends on whether you give other trainings to your child so that he/she can adopt Primiary school. In terms of disciplinary, both are strict enough to make sure you child will be a "good" child.