The areas you need to address are *safety- ie is it safer for your child to get to the out of area school- no main roads etc, bus route near your home.
* Work/emergency care- is the out of area school close to yours or DH's work so the child wouldn't need after school care for as long or at all? Do your emergency contacts live in the area for that school ? Is it easier for them to get your child in that school than the local in area school?
* Social- are all your child's friends form preschool going to that school not your local school? do you have relatives or close friends who attend the school?
* After school care? If you use it does either school have it? You are in a really good position to get in out of area if you need after school care/vacation care and the other school doesn't have it.

Many schools will take out of area with no questions asked but some are very popular and will refuse any out of area. My school has already sent out their out of area acceptances so you need to hurry up and enrol because the longer you leave it the harder it is to get in.
If you need any advice please ask as I am a teacher in the NSW state system.