Personally I prefer Wellington over Auckland - why not look into it? A large part of Auckland city is a collection of suburbs which I never warm to, whereas Wellington feels more like a city with outlying towns. It's very clean and attractive too and even in the city centre feels friendly. Lots of lovely coastline too.
As for lifestyle - NZ is very different class wise to the UK - there is no system, so work life balance, outdoor lifestyle is probably where you'll find the difference. E.g. we are in a cheap rental at the moment (temporarily) and are living next door to a doctor (in the same type of house) - just to give you an idea of one of the major differences we've found here. :-)