WTF. I don't get how people say Auckland is unsafe. I've lived here for pretty much my whole life and I have never run into any trouble. I'm often in town on a Friday/Saturday night usually till around 4am and I've never gotten into a fight or anything. I usually walk home by myself and have never had any trouble. People don't carry weapons here, and if you do ever get jumped or whatever, your not going to end up in hospital.
If I compare it Melbourne (where I lived last year) I had probably more trouble with flipped out P heads then I ever have had in my whole life. There was multiple occasion where I thought we were going to be jumped by Samoan/Tongan people (maybe it was a coincidence but it was every time) and I found that if you talked to them, most of them were from South Auckland so after I got talking to them they seemed to leave us alone. But once again, nothing like this has happened before in NZ.
You honestly never see gang people around, you never see people cracked out of their mind walking around Queen St/K Rd.
I've only been in to LA once but I imagine Auckland would be a lot safer due to the fact that it's a much smaller compact city and there's no guns here. Plus the number of cops around has literally quadrupled in the last few months from what I noticed. It's kind of annoying cause they literally pull over 50% of cars driving through K Rd but hey whatever least it's safe.
It really depends on where you are. There is a lot of gang activity in the more impoverished areas - even though NZ is a welfare state the benefits are set at a starvation level, which leads to the associated crime.
It would pay to ask locals what they think of an area before moving there. In general it's fairly safe though, the big gangs are more interested in selling pot than getting locked up. The youth gangs are full of angry teenagers as usual, but they're not a big issue. You can walk down the nightlife areas at 3am and not get mugged unless you go down a dark alley.
My background - expat brit who moved here for high school, been here for 16 years now. Lived in the lower north island for all of that time.