NZ seats are longer and wider than AC. http://www.seatguru.com/airlines/Air...ng_777-300.php

Also it is a pain to flip the seat down on NZ, but that extra effort plus the larger seat is an hands down win for NZ, its a long flight to sit in AC's uncomfortable coffin.
Also do drive, its easy and you will get the hang of the "wrong" side of the road quickly. NZ has lots of tourists so the roads are well marked with arrows.