UNSW: STEM >>>>> and laughable commerce, law and med when compared to USYD
USYD: maths is 100000x harder than unsw due to having to hand calculate everything and shit there is a tad bit outdated compared to unsw, esp their comp programs and engineering degree requirements but they are getting better. Their social sciences and med are far better than UNSW's.
Anything else, either uni is generally fine, really depends on the degree you wanna do ngl and no matter what degree, youre bascially comparing apples and a slightly larger apple ykwim.
I will say, tris are hell and UNSW is cringe asf for having them.