Advocates of Senate reform (particularly direct election of Canadian Senators) have taken to citing Australia's Senate as evidence that elected and democratically legitimate Senates are compatible with well run societies (here, here and here). They should desist, unless they are prepared to advocate for an actual Australian model Senate, which is quite different from the one they are proposing for Canada.
Australia's Senate is Elected by Proportional Representation
This is almost certainly the most important difference. Canadian Senate reformers are advocating Senators be elected by Province in the same manner we elect House members - first past the post. How that would play out in multi-party Canada is unclear, though likely it would continue to allow a plurality support party to win a majority of Senate seats. I fail to see how two Houses of Parliament elected by the same system improve Canadian democracy.
Australia's Senate has Limited Powers
Australia's Senate is not allowed to originate or (this is key) amend Supply bills. This means the Government's budget bills (from the House of Commons) are take-it-or-leave-it propositions. The US Senate is supposedly prevented from originating such bills, but with the power to amend them, this limitation proves essentially useless. The US Senate, when it wants to pass such a bill, just takes any old House bill already passed that chamber, and "amends" it by stripping its contents and substituting a new bill. Canada's Constitution has a US style provision and I expect it would be equally ineffectual without an Australian style limitation on amendment powers to money bills.
Australia's House has Powers to Override the Senate
For brevity's sake get the details here, but briefly the Prime Minister has some ability in extreme circumstances of the Senate blocking something, to force full elections of the entire Parliament and if that still doesn't get a Senate willing to pass whatever bill, the PM can initiate a joint sitting where House and Senate members get 1 vote each, and the much greater number of House members will probably cause the measure to prevail. The first power (double dissolution) has been used six times already, and the joint sitting power was needed only once, to bring in Australia's system of universal health care during the 1970s.
The regular need for these override powers even given the extremity of causing an additional full national election campaign to do it should caution Senate reformers as to the general obstructionist nature of Senates that have the power to behave that way. In a Canada that had the Senate our reformers are pushing, could national universal health care have come to be?
Still, even these limited powers and capacity for override did not prevent the Australian 1975 Constitutional Crisis where the Senate was blocking supply to the government, and the Governor-General decided he was therefore required to dismiss the Prime Minister (who still had confidence of the House) and force new elections. A person on Twitter asked me if one crisis means their entire system is unworthy, and my answer is "maybe" - it depends how bad the crisis is, or could have been. That crisis was not only about the role of the Senate, but the unelected Governor-General dismissing a Prime Minister but we would be foolish not to observe that incident and ensure it could not happen in our system.
It would be an exaggeration to say Australia is some kind of failure. It's a prosperous country and ahead of Canada in a number of developmental areas. Yet it's clear that their Senate is nothing like the one reformers are pushing for Canada so we really can't draw much on their experience, and even then they have had significant troubles with their model. I maintain my belief that the most sensible reform is abolition of the chamber, but if reform must be, I would vastly prefer the Australian model of a more democratically elected Senate, with limited legislative powers and which can be overridden at need to the model being pushed for Canada.