I hate to say this because we love and support our 'cousins' in Christchurch, and we only visited Christchurch for the first time after the earthquakes, but the place was a dump, and pretty scary with drunks vagrants and crime. Definitely not somewhere I want to go again any time soon. (Maybe in 10 or 15 years)
We found Dunedin to be alright. I'd probably most like to live there one day.