I'm an American (from Wisconsin) who came here to do uni full time (not exchange). Unfortunately, I didn't go to any of the schools you are looking at, so I can't say much. I went to Deakin University, which is in and around Melbourne. If you have any questions about moving over here or anything like that though, feel free to ask.
One bit of advice.. book a flight with Qantas if you can. They have the better service and have nicer planes (on a 12-13 hr flight, those little personal TVs are a godsend).
That said, I'm flying to the States and back these Christmas hols on United (who partner w/ Air NZ). I saved about $700-800 going with united, so it was hard to pass up. I haven't been on one of these trips on a united plane in a few years.. here's hoping they installed those little TVs too

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