You're right Auckland layovers are rare these days...although, we did have them at one time when we used to fly for Malaysian Airlines.

The AKL flights are now generally operating JFK-HNL-AKL-MEL with a stop in LAX sometimes...Crew change in in HNL.

SYD...we used to stay at the Marriott in downtown (not the one near the Sydney Opera, but certainly within walking distance...and a good location. We have recently changed hotels to coogee beach - Google Search