Estimado AngeleToR,
I have been out of the NZ ATC scene for a few years now, I can't really comment on the current terms and conditions there apart from what you see already on this thread. I do however fly over your country on an almost daily basis it seems.
Lifestyle and climate wise: NZ is probably the mildest place in the world on both counts. Don't expect anything racey, the North West of Spain looks very much the same in many senses, but at least you get a guaranteed summer in Asturias! The family ties and sense of local community in Spain tend to be much stronger too, curiously reflected in the homicide rates and violent crime, which in Spain are far less per capita.
That being said, the population is NZ is so small unless you live close to a disadvantaged group your chances of harm are probably low!
Madrid has a High Commission rather than an embassy, but I certainly wouldn't rule out a taster by way of a holiday which should include that big lovely western island swarming with flies as well.
I know the crap time you've had in Spanish ATC, but the grass always seems verdant green over the fence, and in the case of NZ it probably is , a peso paraque la lluvia.