My wife and I went to NZ for two weeks, it was absolutely fantastic. If you like big city stuff, lots of people, very busy areas, then you're better off heading somewhere in asia (like Japan). If you prefer relaxing, fun, outgoing, activities, NZ is the place to go. It's beautiful, lots to see and do. The whale watching (if that's something you're interested in) is amazing, I'd love to do that again.
Go check out some of the Maori towns, go to some of the volcanic areas, go see mount cook, the glow-worm caves, etc etc..... It's a great country. If it wasn't so far removed from my family and friends I'd try to move there.