Ferris, Sean O'Brien and Jamie Heaslip have formed the tournament's most effective partnership, though Wales and New Zealand are pushing them close.
There are few more destructive ball carriers than Ferris and O'Brien, the flankers whose physicality has identified them as Ireland's outstanding players.
Number eight Heaslip has shown a remarkable appetite for work and is the only member of the squad to have played every minute of all four pool matches.
"We fancy ourselves against any back row at the World Cup. Given the way we're playing we'd rate ourselves against anyone," said Ferris.
"It's great being a part of this unit. Sean has been fantastic. The Italy game was only the second time I've started with him.
"Every time he carries the ball you're looking to run off his shoulder because you know he'll break the first tackle.
"Against Italy he showed the world what he's made of.
"Sean thinks the same of me and we both think the same of Jamie.
"We seem to be clicking very well and sharing the workload. The balance is good - it's worked well so far."
The back row has spearheaded Ireland's march into the quarter-finals, where they will meet Wales in Wellington on Saturday.
Victories over Australia and Italy, who were ruthlessly crushed 36-6 on Sunday, have identified them as genuine contenders to reach the final.
"Coming into the World Cup we talked about taking it game by game and that's what we've done," said Ferris.
"We need to approach Wales with the same attitude - the only thing that matters is beating them.
"Wales are playing some good stuff at the moment. We watched them before we played Italy.
"They looked very silky and it will be another massive contest for us. But the way we're playing at the moment we can beat anyone.
"Over the last couple of years we've been capable of raising our game - just look at the 2009 Grand Slam, beating England in March and then Australia here.
"Every week it's getting bigger and bigger. The prize for beating Wales is massive as it will mean we're here to the end of the tournament.
"All the focus will be on doing a job on these boys."
Ireland lost all four warm-up internationals yet have so far proved one of the success stories of the World Cup, prompting Ferris to draw similarities with England four years ago.
"Australia was a game we knew we could win if we played to our potential, but there's more in the tank," said the Lions flanker.
"We feel as though we're progressing game by game. Against Italy we showed we can be clinical and our decision making throughout was exceptional.
"The way we're playing, we have to be ambitious. England four years ago didn't have a good record coming into the competition but reached the final. Hopefully we can go one step further."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.