Having caught a few of the Sydney-Hamilton NZ flights since it launched, I have to say it has been a reliable service to get to the mid-North Island of New Zealand. I have caught 10 flights between the 2 cities, most has been midweek, and the load factors have been consistently high in both directions.
The 3 hour fight in a Jetstar narrow body seat is perfectly tolerable - my preference is when they utilise the newer aircraft with the USB-C charging port and device holder. The Hamilton airport does not have jet bridges, instead they utilise a staircases at the front and back for boarding and disembarking and will employ an elevator for passengers with a disability.
Departing from Hamilton, I was surprised that security used a 'modern' X-ray machine meaning I didn't have to take electronics or liquids out of carry on bags. Unsurprisingly immigration is processed manually. There is a cafe before and after security that makes decent coffee. The departure lounge is fill of natural light, though it can seem crowded when there is a full plane, but there is enough seats for everyone.
What I like the most about this route is the friendly staff at the Hamilton Airport side. I am so used to the treatment from grumpy Sydney staff I had almost forgotten what it's like to be greeted with a smile. Here's hoping this is a sustainable route that lasts (and catches the attention of Air NZ/Qantas).