A good question.
A local answer.

If the inbound flight is on time and bags can be checked early, a brief Circular Quay visit may work. Decide at the airport using the actual arrival time.

Check toll coverage, kilometres and insurance excess before booking. Reserve early if the weekend is busy and confirm where keys are returned after hours.

Map both properties to the outings you will repeat. Pitt Street may suit CBD shopping while Sussex Street may feel closer to Darling Harbour activities.

Visit more than one established dealer and compare stones in consistent lighting. Ask whether each is solid, doublet or triplet and where it was sourced.

Choose by current menu, location and opening hours, then look at recent reviews for consistency. A famous name may not justify a long journey for one burger.

If a missed onward flight would be expensive, allow a longer connection or an overnight stop. Separate tickets may not include protection when the first flight is delayed.

For several weeks, groceries, laundry and a comfortable room matter as much as the first day's attractions. Check the street and room noise before booking.

Compare the exact room category and current inclusions at both hotels. Breakfast, lounge access and harbour-facing views can change the value considerably.

A rental car can simplify access, but confirm parking rules and your driving route. A guided walk may suit you better if you do not want to navigate the track alone.

Check the event-specific rail plan and your flight's check-in cutoff together. Stations and roads can both be busy when the crowd leaves.

Compare the walk to rail or ferry with the space you gain. A slightly less central apartment can be worthwhile if the family has room to unwind.

Use the official traffic service for incidents and roadworks on the day. Keep the scenic coastal section for daylight rather than trying to recover time there.