Oh! Well, I'm not really an expert, since I don't even live there yet, but there seems to be the older established houses on one side of the train tracks (the Maccas side), and then the estates like Heritage Springs, Henty Park, Arden Estate and...the one with the blue street lights, on the side closer to the bypass.

I guess you wouldn't necessarily know if you were in an estate if you didn't build/buy it new, I know ours because we bought it and I know some others because they have big signs.