On the plus side here is what I do like with NZ:

IFE is fine.
Website/mobile app does what I need it to.
On-time performance seems fine, have only had a couple of weather delays when flying nationally, and internationally I seem to remember being on-time or early.
Boarding process in general seems to work, and I get priority boarding almost every time.
Baggage allowances are fine both carry-on and checked, haven't had a problem with late/lost luggage yet (touch wood).
Call centre seems fine from the few dealings I've had.

Airpoints Gold is worth it for me, I like the lounges flying internationally, nationally I could take them or leave them as I tend not to be at the airport too early.
*G status is great when I'm flying United in the US for priority boarding and free bag