I wouldn't take QF. Not only are they not obliged to tag bags through to a NZ flight (although they probably will), the on time performance is terrible. The small terminal size at CHC (although QF dom is far other end from international) is irrelevant if QF arrives say an hour late (not that unusual).

As for NZ, ATR is more comfortable than 733 IMO but surely there is a nonstop flight you can take? 2:40 on ATR vs 1:20 on 733.