Ahh, Groobie. You missed out on so much by not coming to the South Island (or the mainland, as we in NZ call it!). I was technically born in Hamilton, but only lived there for 3 months, so I've always thought of the SI as my home (although I lived in the Solomon Islands for 3 years in between Hamilton and Christchurch...).
Make another trip and come to the SI!
It's absolutely worth it. I may be biased, but I don't think a trip to NZ could be a proper trip without going to both islands.
~Anna.