I live in Mt Barker and love it. The rush hour traffic on the freeway is busy but is nothing compared to UK rush hour!!. There are several good schools in the area. As you will see from the chat here, quite a few people send their kids to private schools which are affordable (we did ) BUT knowing what I know now, I would not waste my money on primary school years in private.
There are great sporting clubs, loads of places to meet people and generally fantastic(obviously I am biased!) We would have like to live near the sea but it was far too expensive for us, so the Hills won the day.