When Amex canned its points transfer to NZ Airpoints, it spelt the end of my relationship with Airpoints.
We transfered all our points to the one account, then bought seats with all of our points, ended up with 94 points spare which i used on a Christchurch Nelson - and paid for the return.
Now we collect points on NAB (National Australia Bank) Velocity , 2 points for every $ on Amex and 1 point for every $ on Visa. These points transfer automatically to Velocity each month, they have no expiry date - and there are lots of options to use points on Virgin Blue, Virgin Atlantic (and soon to be announced V - Australia) also a bunch of partner airlines like EK.
We fly domestic in Australia on Virgin Blue and Internationally on EK or VS.
Works for us, and while we always enjoyed our relationship with NZ - its all about loyalty. NZ and AMEX choose not to be loyal to us, so we did the same.
Adam