Close to zero
the only difference is ur apply for a graduate job at an old-school firm or something, and it comes down to a Macq and a USyd graduate, with exactly the same academic qualities, and the same interpersonal and other skills, then...the USyd graduate might get it ahead of the Macq...but thats all speculation anyway
it all depends how you are as a person, and how well u do in your law subjects, no matter what uni u goto