We have always been in the eastern suburbs. Most of our friends/relatives also live in the eastern suburbs so we know the eastern suburbs well.
We have really enjoyed living in this part of Sydney (in fact we are really comfortable with the areas) and would not want to move if we could afford to upgrade here. It just doesnt seem to be the case at the moment.
Sure we know other parts of Sydney but we dont know what it is like to live in other suburbs. On top of that, the wife doesnt drive (she has a fear of driving) so that also limits her (and us to certain extents) only to areas with good public transport coverage.