Among IB/JC/NUSH/Poly who does well in NUS CS?

Assuming intake for IB/JC/NUSH/Poly are equal for all groups, is there a common consensus of which group of student does well and does not GPA-wise in NUS CS based on their background?

I am personally a prospective NUS CS student from Poly (ICT-related) in NS and I am quite worried if I would do well given the course's competitiveness. Do poly students do well and if not what traits/knowledge do you think they are lacking in and can prepare? Thanks!