I went public. There's a good one across the road. You can check them out at myschools (https://www.myschool.edu.au/) to make sure you are getting what you paid for. I don't think that there is a great deal of difference at primary level. Also, there is no evidence in Australia that Private schools are any better than the good public schools (i.e see http://www.abc.net.au/news/2015-04-14/study-finds-no-academic-edge-for-private-school-students/6390936). It will depend on your suburb and SES.

In W.A we have a once a week pull out program called PEAC (http://www.northmetropeac.wa.edu.au/early_years.htm) that caters for year 1 upwards if your child is advanced. I expect that N.S.W would have something similar.

I tend to try to use the school system as a free supplement with the aim of staying 12 months ahead so that they are reviewing what we have already covered. So far so good.