Providing you can get visas for either, then you're spoilt for choice. I've never been to NZ, but really want to go there. The weather seems nicer, and the topography more varied and within easier travelling distance. On the other hand, it's a much longer flight to civilization than Australia, and also the NZ government have been running a programme to try and entice NZ citizens back to the country because so many are leaving. In fact around 55,000 move to Australia every year, so that might tell you something. Also, people with Australian PR or nationality have more rights in NZ than people with NZ PR or nationality have in Australia, so that might be another thing to consider for long-term plans.