I love NZ... but I live in Melbourne, Australia and there are tons of kiwis here (including many close friends and colleagues). They come here because salaries are better, adjusted cost of living is less and there are just more opportunities for professionals. Australia isn't perfect but I'm not really sure that NZ is a more attractive destination for tech workers.
Yeah, come to New Zealand because you like mountains and temperate rainforests. Not to advance your IT career. I think in 20 years time that may change though - the tyranny of distance applies less to software than other products.