There are obviously some areas of Armidale that aren't as desirable as others...... There's a railway line , so suppose you wouldn't want to be right next to that. Some areas close to the university have more 'student' type accomodation. We lived on the south hill, but have friends dotted around all over Armidale. I agree that you should rent first if possible. It won't take you long to get a feel for the place, and which areas are the 'best'.
We found it to be a lovely, friendly place. The Centro shopping centre is good, and as most places in Australia, has free parking!