Both 600 and 601 visas are solely for travellers wishing to enter Australia as a visitor for leisure or business purposes. The difference between a 600 and a 601 visa is that the 601 allows for a maximum stay of 3 months. Moreover, the 601 visa demands less, if not zero, paperwork. This is because the 601 is available only for a specific set of passport holders, without prior criminal convictions nor debts towards the Australian Government, can apply for a 601 visa. Presumably, the 601 visa is the result of a bilateral agreement between Australia and all the listed countries. All travellers not meeting these criteria must apply for a 600 visa.
To answer your specific query, you should apply for whichever visa you are eligible for. If you have the choice, pick the cheaper and simpler option. Note that this could even be the eVisitor (subclass 651) visa, depending on eligibility.
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