My hot take: (lived in NZ, Aus, NL and USA)

Both places are are similar in that:

  - They have good access to nature/beaches
  - Property prices are nuts, most people see property as their primary investment vehicle. This is a big cause of wealth inequality
  - general populace has a relatively easygoing disposition

Aus has better weather (assuming you like warm and sunny), higher salaries and is somewhat less far from the world if you want to travel

NZ has a better human rights record, much cleaner grid, and doesn't seem to have the authoritarian bent that Aus does. It's like the slightly hippie/socialist/woke little sibling.