Speaking at the launch of the show's new series earlier this month, Nick admitted that he and Karren are sometimes surprised by who Lord Sugar fires, and insists they never know in advance.
"Sometimes we disagree, but more often than not he's proved right," Nick told us. "He's as smart as a whip.
"In terms of the contestants, he has considerable insight into people's personalities. He’s a great judge of character."
Nick also praised Lord Sugar for being the reason that the show is still on the air after eight years.
He explained: "While there are so many elimination shows in the TV schedules, The Apprentice has something special.
"And to that, you've got lord sugar who is an extraordinary performer, a real original.
"Plus, I think people of all ages are interested in business and money and profits."
The Apprentice 2012 starts on Wednesday night on BBC One.