Not criticising in any way the Marathon unit, but Chien Wah are most definitely the superior dialy dimmie. Not that they're easy to find since Colesworths stopped stocking them, but worth the effort IMHO.
Sth Melb's definitely the reigning overlord, I'm sure everyone would agree.
Sth Melbourne ones have a lot more flavour than traditional dimmies.
I know a little lunch shop in Braeside, called "chop chop" ( no illegal tobacco there ), they make their own dimmies, and sell them frozen by the bag as well as for take away. Wouldn't say they are better than south melb, but they are different and good.