When all is said and done,if you have young Children, like the wide open spaces, beautiful beaches, clean air ,Surf lifesaving clubs, plenty of good shopping centres, good schools, primary and secondary. then head south of the City.
If not, head the other way.
I don’t know where you got your information from but I would hazard a guess its from some that don’t live down that way.places like Happy valley, Noarlunga, Seacliff etc, but some say these are run down.
Just have a drive around those areas and you will be pleasantly surprised.\As for the North being up and coming I cant see how it can be unless you go as far as Port Adelaide where there's some construction work going on and will probably finish up like Canary Warf,(Not for your average Jo worker) apart from that, North, N/W, N/E has nowhere left to Build closer than Port Adelaide.
South, S/E,S/W would be my choice, I would include West but I find it a tad over priced.
Good luck with your research.