I am a Kiwi, my husband is also a Brit. I have lived in the UK for nearly 15 years, first in London and now in Manchester. I have loved the UK and its culture, there are lots of beautiful places in the UK and okay the weather is a bit shit but I am from Dunedin so it has not bothered me 
But my situation is slightly different to yours - my dad died as a teen, I am an only child so only have my mum around. My mum has the money to come and go from NZ to the UK. I also get on extremely well with my in-laws so they have become a second family.
Honestly? I could not move back to NZ, maybe its because I could only find jobs in Auckland or Wellington. I loathe Auckland with a passion and have barely any ties to Wellington. I would want to live in the South Island so I do not see any point living in a different island and paying AIR NZ ridiculous domestic flight costs.
The price of living is astronomical (petrol, groceries, electricity, rent etc). Sure the scenery and beaches are nice but it does not pay the bills. Its too isolating, I love having Europe on tap, secondary schools are great in the UK (having had friends kids go through NCEA in NZ it sounds very shit and confusing as fuck). There are also far more opportunities in the UK, things to do.
However we are moving to Australia in a month, I got offered a job (would not have left the UK otherwise) there and we are going for three years as a compromise with DH (he is very close to his family) so we can nip back and forth from Melbourne to Queenstown (can be cheaper than domestic) and our DC can see where I grew up, but I also have a lot of friends in Australia and have previously lived in Australia.
I accepted when I married DH that I would have to remain in the UK because of how close he is to our family. DH is happy to move to Melbourne for a couple of years as he sees it as an adventure but not permanently.
You really need to have this discussion OP about where to be based before children, mortgages etc come along. Because if you do not like living in the UK (miss family, beaches etc) and you have children there, you will become trapped in the UK if your DH refuses to leave or you seperate. Dual nationality marriages are really difficult to navigate, compromise is the only way for both of you to be happy. Whatever that compromise may be.