I think people just like to talk about the terrible things, like if you have a baby everyone tells you all the gorey stuff. Don't be put off, I am phobic about spideys but honestly it's fine in NZ. Yes there are some, but I have no horror stories to tell. And I have to keep reminding myself that the spideys eat the sandflies, and THEY are a pain in the rear (or wherever else they bite you!). Sandflies are the evil cousin of the Scottish Midge - argh! Anyway, the good far outweighs any bad in NZ, so if you have the opportunity to get here, go for it!
Jules