I live in melton and work in melton south......whilst it does attract more loc eco individuals, the rentals seem to turn over there quicker, due to it being close to the train station, public transport and shops. Its more like the frankston north of frankston, I also earn a rental there. Great if you can get a large block, those cement houses are solid and harder to damage, and slowly the worst of the worst are moving away for cheaper areas.
Your right, there is average capital growth around melton, I think it sits around the 7%.
The new estates, whilst great, lack public transport and are generally miles from any local convenience (schools/shops/drs etc), this is where melton south will gain in the future and always be good for rentals. Larger blocks are still available in the older areas like melton south, so subdivision may be the way to look at increasing your potential capital gains/growth