i lived in nz for 7 years and loved it...though did eventually move back....its a fantastic lifestyle but there are good and bad points, heres a run down of a few:
good
cheap houses
friendly people (generally)
easy to settle in (quite an english feel particularly in places like christchurch)
very outdoors focussed and loads of sports clubs etc you can join
bad
its expensive to fly back, especially when your on an nz salary
its hard to stay in touch as the time difference often means its late/early for one person
english humour doesnt always travel well....but could have just been my jokes!!!
all in all its a great lifestyle though and we would have stayed there if we could have persuaded friends/family to join us. however, in the end it was too far from home and too hard to say in touch and we couldnt give that up so moved back. its a great life if you can make it work though 
hope that helps as a good balanced view