I can't say I have anything to compare it too but I'm just about to finish my first year and I've loved it. I personally love having a smaller class sizes, its a bit less intimidating. The only downside I have is the sheer size if the campus and it's a lot of walking but that's not a bad thing. I guess it depends on what your studying. One of my friends was told not to go here for her physics degree and now she's at Macquarie so there's a lot of factors that affect it.
Who knows. We aren't as prestigious as some Sydney universities I guess. I've personally never heard people saying it's bad but I know people consider the popular sydney uni's to be better. Then again, we have people commute from Sydney to come here so who knows.
No, it's not bad. I've visited literally ever university in the country for my work (excluding only Charles Sturt Uni) and UoN is good. It's a nice campus, people are friendly and it has some areas of real academic strength. Everybody has some kind of agenda when they say crap like that - the truth is that every uni has SOMETHING that they are awesome at, and even high "ranking" unis can be terrible at some things.
It depends on you and what you want to study. Which is...what?