I'm going to post without reading all other posts so excuse me if I repeat what others have said!
Have been here 13 years. Married to a kiwi. Have 2 boys 15 and 10 so both at school. Let's get the negative over first....
It's a long and expensive trip back to the UK. You will miss out on key family events (births, deaths, watching nieces and nephews grow up). Family guilt can be huge. It's not the UK don't come expecting it to be the same. It takes everybody different time to settle and it took me a few years.
If you love culture - theatre, architecture etc... Auckland is somewhat lacking. You can't jump on a plane/train and immerse yourself in a different culture quickly and cheaply.
Now the pluses.........
Weather - yes it rains but summer is long and glorious
Auckland housing is expensive but like anywhere it depends on where you chose to live. If you are looking at AKL/Greenlane Hospitals you can live anywhere and easily commute. Everybody has their personal preference - I live South, we have a lifestyle block, commutable to City, train, ferry all within easy distance. I love the multicultural feel to the South (North and West don't do it for me). Could easily live in Mission Bay etc... but houses too close together for me, I love the feeling of space. I'm 20 mins from beautiful beaches, live semi-rural, so enjoy the best of everything. We paddle board after work in summer (tide permitting), have BBQs on the beach etc...Don't have a pool at this house, but putting one in. Boys have a few acres to run wild in (ponds, weeping willows, ducks, veggie garden etc...)
We have a beach house an hour away where we spend most of summer and odd weekends over winter. The boys surf, boogie board, we play tennis, bike ride. My boys enjoy everything I did growing up in the UK (many years ago!!! lol)
I have had no trouble getting work - have been head hunted for 3 jobs. I guess work depends on your field (I also work in health related field). I have been able to negotiate hours and work from home during school holidays.
Primary school is great, class sizes approx 20 children/class. I wasn't impressed with High School so DS1 went to private school for intermediate and year 9 (Cambridge system). He hated it. We moved him to a state school (with a good reputation) and he is thriving. Loves the subject choices and holistic learning environment. He's opted to take Electronics, Ecomomics, Business and Finance this year as his options.
Both boys play sport (rugby, soccer, touch and league depending on season), have had riding lessons, swimming lessons, the list is endless. Kids sports cheap and accessible.
Swimming pools in Auckland are free.
That's off the top of my head. I would tell anybody to give it a go - if it all goes wrong, you can go 'home'. For us it was the best thing we did for the family (NB if I didn't have the boys I would live in Europe and there is always the chance they will uproot and go to the UK at the first opportunity but I'll cross that bridge when I come to it....)
Will read rest of posts at some stage and see if there's anything else I can think of.