Hello (: I'm a student of NJC.
I'd say that we are not very academic oriented, the environment here is really nice and friendly, not a stressful and competitive ground. I liked that especially as personally, I'm not someone who wants to 'mug' all day long and achieve superb results at the end of the day. The curriculum also enforces on character development (; We are given many opportunities for leadership stuff.
In Sec 1 & 2, there isn't any 'major exams' like primary school's CA or SA. But the system works with many little small graded assignments (Eg. a project that constitutes 20%, a class quiz that constitutes 15%, a debate/role play that constitutes another 25%, etc.) I think that makes students less stress about school work, but at the same time we are still learning what we are supposed to
In Sec 3 & 4, there are still such projects and assignments that are graded, but there will also be 'major exams' that will take up a relatively huge portion of the grade.
In the IP programme, we are given many opportunities to develop our character and not just focus on academics always. We are also being exposed to many fun activities (especially during the Boarding term) that help bonding within and between classes/houses (: The curriculum is also specially made (we don't usually use textbooks outside except for some subjects) to better prepare us for A levels, instead of the usual O levels style. And some things we are learning are the 'simpler' and more basic things that other students only get to know in JC1.
It is true that the school is better at Maths & Science. We are also exposed to doing research in Sec 2 & 3 (most people choose Science, some Maths) and we will work in groups with a teacher mentoring us. Some students get to cooperate with researchers from universities and polytechnics, and some will be chosen for exchange programme with various countries. Hope this helps!