Personally, I'd go UNSW. Both are easily on par with each other in terms of education and employment prospects. It just all depends on your own circumstances (Which Uni is closer, which Campus you prefer, etc). So you are free to judge superficially lol On the surface, where it counts! haha. Both have similar cut-offs (99+?), and both are highly regarded within Australia, so it's just down to where you prefer. I'm all for Team UNSW, but that's just me lol
I just think that all of this building up of USyd as 'prestigious' is kind of funny. They're trying to recreate their own mini-Harvard, but to no avail. Ask anyone overseas, and they will know nothing of either USyd or Melb for that matter. It's a just a case of a small community trying to desperately create their own reputation of 'elitism' and 'prestige' by methods of exclusion. The only Australian institution that is even remotely compareable to the United States' 'Ivy League' is in fact 'ANU' (But that's in Canberra, and who in their right mind would ever want to live there!? haha)