Last Fri, Mel-Akl (VH-XZL) and on Sat, Akl-Mel (VH-XZN), there was Wifi all the way across the Tasman....it did drop out for periods of time but when available, I could stream the AFL footy on Kayo Sports :) I did not test the speed.
What was also interesting, as I did not have a NZ SIM card...