Just to contextualise your question;
What do you WANT usyd for? Will it get you employment overseas (more likely than other universities), how? It is attempting to internationalise itself. That being said, why not UMelb? Why not Monash? Why not ANU?
Because Usyd and UNSW reside in the same state they are often compared, but when you look at the larger picture, the country, hell even the world, neither really make much of an impact. Goodluck getting a job in any country other than Australia with a specialised degree from either.
There are specific advantages for Usyd I must admit, most namely, the connections one could potentially aquire, this isn't some 'im from usyd we're the best' thing, but if you look at the demographics of the people that attend such a university, they are certainly more affluent, or if not that, ambitious (as per the higher atar require for courses). A lot of people can say the same for UNSW, that's fine, and may certainly be true, both are top universities in Australia.
BUT ultimately either way you slice it, YOU ARE a tiny fish, and the only reprise from that fact is when you're 65 and looking at the wall in your study or office, would you like to see University of Sydney, or another name?