The Lions fell to an agonising 2-1 Test defeat to South Africa in 2009.
After making an unbeaten start to their tour, Sir Ian McGeechan's men fell to two narrow defeats before coming out 28-9 winners in the final Test.
And the fact that the former Springbok coach rates Australia alongside New Zealand as the number one side in the world demonstrates the magnitude of the Lions task in three years time, especially as the youthful Australia squad is only going to get better.
"In my opinion Australia are today the best team in the world alongside New Zealand," said Mallet.
"They beat South Africa twice in the Tri-Nations and in each of three Tests against the World Champions they scored at least 30 points.
"Not everyone can do that. Their backs, alongside New Zealand's, are the most dangerous in international competition and the new interpretations of the laws favour their way of playing and their attacking characteristics."