Hey Tracey Turk - we are arriving next month and my son will also be in year 6 (I have another in year 3). We're from Sydney too.
I thought AIS looked OK, and one of my son's (Sydney) classmates went there for a year and told him the canteen was really good
I'm not worried about the NSW/Australian curriculum - if your expat package includes school fees (ours doesn't) my top pick is UWC Dover - great academically, and their extra-curricular program seems much bigger and better supported than AIS (for example, they host swim & basketball squads on their grounds, have a jazz band and orchestra etc.).