Hi,
I'm not sure if I can help much, but my husband is an upper primary teacher at the AISHK, so I can tell you a little about his perspective and what I know and have seen there.
My husband came from private schools in both Canberra and Melbourne and rates the AISHK as being up there with the best in terms of learning and development. The teachers work very hard (in fact, I have not seen him work so hard!), my husband says the leadership at the school is second-to-none and that they have great resources available to them. One thing my husband has particularly noted is the commitment the school has to ensure an adequate balance between the Australian and local cultures.
I am sure that there are both positives and negatives, but a good indication is that my husband would love our daughter Ally to go there if we are still in HK when she is older!
Hope that helps a little,
Jen