I believe the M1 is well liked by crews however they are very heavy....too heavy for much of our infrastructure especially in the north of the country.
"at 70 tonnes the Abrams tanks are notoriously heavy—and the SEPv3 models are even heavier. They’re too heavy for our amphibious landing boats and for many of the underdeveloped or degraded roads and bridges in our near region, as well as in large parts of Nth Australia
While the army should continue to operate a tank platform, the Abrams is simply too heavy for Australia’s needs. The M1A2 SEPv3 is a continuation of the army’s tank capabilities: fast, powerful, reliable and overkill and overweight for Australia’s needs, with little room to manoeuvre for future developments. "