Consumer NZ, in their latest magazine issue, have done a report and comparison on the reward schemes of the different credit cards available in New Zealand.
Of interest is a flight rewards table rating the percentage of a return AKL-SYD flight your reward points will pay for after 2 years of use and standard fee deduction ... without incurring extra fees (like interest and penalties).
BNZ/Amex cards sit on top of the list, with their classic card paying 1.8 times the airfare.
Worst performing are the cards are dominated by the ones that have the most annual yearly charges (Platinum/Titanium). The Air NZ Amex Platinum card is not in the list but would be likely be in negative territory and only of interest for people wanting the free airpoints and return flight.
About a third of the cards had negative net value, so all the points benefits are swallowed up by extra charges.
The other comment was most these cards have the highest interest rates and are not worth it unless you pay the full balance monthly.
I'm just defecting from a GlobalPlus Gold/MC to ANZ Platinum/Visa so I'm going up on the scale a bit (glad I didn't go down the easy road and upgrade to the GlobalPlus Platinum ... as its rating is well in the negative territory). But my main motivation is the annual subsidy to Koru that makes it much more worth it