But who else offers dual-stack by default in NZ? I haven't found any good source of information that outlines what the various ISPs offer. ipv6.org.nz hasn't been updated for a while.

There's a couple of providers that still seem to be running 'trials' - but those pages haven't been updated in years. That doesn't exactly fill me with confidence. Does that mean it could be switched off for an extended period, like the situation here?

I guess I need to go and ring around all the different ISPs, and put together my own table, showing current state. Unless someone else has some up to date information?