Xero is deeply embedded in Australia and its payroll and super handling are mature. HelloBooks is the better answer for multi-entity groups and for anyone whose bill keeps stepping up because of employee counts rather than accounting needs.
For a South Australia business the practical test is narrow: does the product handle payroll tax from a$1,500,000 · up to 0.0495% without you configuring it per transaction, and can your registered BAS agent work in it without another licence? Payroll tax in South Australia has a tax-free threshold of A$1,500,000 in annual Australian wages.