"But we really wanted to bring a point of difference. I think we did that, and this week we tried to come back fighting."
Gap 5 staved off elimination twice, beating out the final two over-25 performers Anna Wilson and Maaka Fiso.
Ione said the show would be a lot more subdued now the group had finally been voted out.
"It's going to be real quiet and boring backstage without us. Everyone's always running about for Gap 5."
Foster had to delay her wedding to allow her to keep competing on The X Factor.
Her ceremony is in a month. If Gap 5 had reached the top two, it would have been a week out from the finale.
"That's crazy, eh," Ione said. "But they're perfect for each other. They're both so lucky to have each other."
Foster said planning a wedding while prepping for performances every week was "stressful".
"I really don't know how I did it, but I got around it. (My fiance's) been really supportive with everything."
Foster and Ione said mentor Melanie Blatt was also a vital support throughout the show.
Even so-called 'mean judge' Daniel Bedingfield was not as harsh as he seemed, Ione said.
"He always apologises for what he says on TV. He comes up and says, 'Oh, was I too harsh?'"
The pair were looking forward to seeing their parents and siblings again after spending nine weeks living in the Sky City hotel.
But they felt the X Factor experience had already elevated Gap 5 from best friends to family.
"It's going to be strange to go home because we're not going to be able to wake up and see each other," Ione said.
"We'll miss that," Foster said.
* nzherald.co.nz is interviewing every artist on Tuesday as they're eliminated from The X Factor.