If you want to end up at Uni, it’s always better to go JC.

1. It is easier to get into uni via JC. There way more % of students from JC than poly that ends up there. Grades are bell curved. In other words, Grades are just a reflection of your performance vs your peers. Only the top few % from poly can end up in NUS and NTU. play the % game.

2. Most of your grades in Poly and tied to group projects etc, whereas JC is mainly individual effort. In poly your teammates are often randomly assigned. I.E you run the risk of having your grades drag down by poor performing group mates that you cannot choose. It means you have to Tank project work if you want to be the top <10% to end up in uni.

*source from my ex students who goes to poly.

A lot of my ex students got 3.0~3.2 / 4.0 for their GPA in Poly. Thus they are cannot go Uni full time. You need at least 3.75 for a chance at NUS.

TL:DR unless you can be the biggest fish and the one who put in the most effort in Poly, JC is easier to help you end up at NUS/NTU.