England defeated Australia 3-0 in the five-match home series in July-August before quickly handing the terracota urn back after three comprehensive defeats in the first three tests Down Under.
The 29-year-old, the leader of the Australian bowling attack, said the credit should be given to his team rather than criticising their struggling opponents.
"In England it was a 3-0 scoreline but it wasn't as comprehensive. Compare that 3-0 to this 3-0, it's a total difference," Siddle told reporters.
"A lot of credit has to go to the way we played - we've been ruthless. We haven't given them anything to jump on the back of. That's what's causing the problems."
Siddle felt the current Australian attack was up there with the best in the world and the team's success was down to their consistency with bat and ball.
"We are up there, aren't we?" Siddle said. "We are winning test matches, bowling teams out.
"But it's on the back of the batters... it does make it a lot easier for the bowling unit as well.
"Just the combination at the moment... we are just playing good positive cricket and being consistent at it."
The trio of Mitchell Johnson, Ryan Harris and Siddle have managed to batter and bruise the England batsmen with their pace and bounce, while off-spinner Nathan Lyon has also played his part picking up 10 wickets.
England have failed to cross the 200-run mark in three out of their six innings during the series and Siddle believed that the current Australia attack was the best he has been part of.
"We've been striving for a long time as a bowling unit to get that consistency right," Siddle said.
"This series has shown that we've been able to bowl teams out quite quickly, give our batters a big chance and be able to put a lot of pressure on the opposition.
"We are bowling well. I think we all are performing well and playing our role. With the ball, I think this is the best line-up I have ever played in."
Australian bowling coach Craig McDermott followed Siddle in lauding his men ahead of the fourth test in Melbourne starting on Thursday.
"I think we've got the best attack in the world," the former Australia paceman told reporters.
"It's very well balanced, particularly with Nathan as our spinner - he's bowled well - and you've got Watto (Shane Watson) there as your fifth bowler.
"He's a pretty handy bowler as a fifth bowler."