>>913993For me it was how many well established and clean hiking trail systems they have. Eco-tourism is one the largest industries on the South Island and it shows. Their gov't has a website set up with all the trails and the important info for them.
New Zealand is fairly cheap to travel around and hitchhiking isn't illegal. You could probably get almost anywhere you needed to go just by hitchhiking.
Lots of different landscapes to explore. No need for special food storage when you're backpacking because the only mammals there are exotic or invasive and none of them are a physical threat.