New Zealand is a beautiful country but the weather is what I would describe as mild and that may not be to your liking.
"In Summer, the average maximum temperature ranges between 20 - 30ºC (68 - 86ºF) and in Winter between 10 - 15ºC (50 - 59ºF)."
https://en.wikipedia.org/wiki/Climate_of_New_Zealand
Life has a slower pace there and generally things are really good. The Māori and a wonderful people and they actively work to maintain their culture. I wouldn't listen to any stories about the bikie gangs and racial issues. They do have some problems but what country doesn't?
And again it is beautiful and I can see why people would want to retire there. The biggest problem for Americans as I see it is the location. It's a long way from The States so if you plan to travel back regularly to see family that can get tiring quickly.