One wants to eat like a caveman and likes Lady Gaga for her "out there" meat dress, the other was once in a bike gang and sold his farm bike to buy an engagement ring for his wife.
The two Davids took a brief break from seeking support in the battle for Labour's leadership to to answer some of the tough questions for the Herald.
David Shearer revealed he had never dieted and seemed puzzled by the concept beyond occasionally skimping on the potatoes.
However, he slightly dented his rugged bloke image when he admitted he was weighing up the merits of the Palaeo-diet - based on raw foods such as nuts, seeds - after friends mentioned it.
"It's eating more like our ancestors did, sort of hunter gatherer-type of food. So I'm trying to move more in that direction.
"McDonald's is the other end of the evolutionary chain from the hunter gatherer."
David Cunliffe said he first dieted in his mid-40s to combat the "Bellamy's bulge" - the weight gain from eating food in Parliament.
He had also dyed his hair - albeit by accident when a National-supporting barber convinced him to dye it bright crimson on the eve of the 1999 election campaign launch.
It didn't wash out and he had to shave his head to get rid of it.
While David Shearer's first leadership experience was the captain of a cricket team in standard four, Mr Cunliffe's was as a patrol leader in Scouts and on a bike gang.
"From memory, I had a little role in a little kids' bike gang, when I was aged 8 or 9. There was a rival gang down the road and we had a lot of fun tootling round on our bikes."
David Cunliffe said his first vehicle was a farm bike when he was a farm worker in South Canterbury before he went to university.
He sold the bike to buy an engagement ring for his wife - with whom he later bought his first car, a rusty Toyota Corolla. For Mr Shearer it was a Morris Minor van which he bought with his own money and maintained himself.
Their choice of either Rihanna or Lady Gaga was different - Cunliffe chose Rihanna, Shearer chose Lady Gaga.
But when asked for their pick for New Zealander of the Year, both men mentioned Paul Callaghan as a worthy winner. However, Mr Cunliffe added that this year Sam Johnson - who put together the Student Army after the Christchurch earthquakes - should be recognised.
First car: Morris Minor van, when he was 18.
Recent trip to cinema: Harry Potter and the Deathly Hallows Part 2. Enjoyed it as much as his children.
First diet? Never. Friends have been encouraging paleo-eating.
Can you dance? Yes. Took formal ballroom lessons once, and wife frequently reminds him that she was better than him.
Nickname: "Dave" to friends.
Ever dyed your hair? No. "Maybe I should before I lose it all and I lose the chance."
Worst plane trip: Trips into Baghdad, where plane spiralled down to avoid ground gun fire while sandstorms came up around them.
NZer of year? Sir Paul Callaghan, physicist.
Lady Gaga or Rihanna? Lady Gaga. "Wearing meat to a performance is pretty out there. And I like her music better."
First vehicle: A Honda 185 farm bike, which he later sold to buy his wife an engagement ring.
Recent trip to the cinema: The Smurfs - with his two sons. Enjoyed it so much they later bought the DVD.
First diet? Mid-40s. "People talk about the 5kg bulge you get when you come to Parliament with Bellamy's food and I've tried to keep that off."
Can you dance? His wife will tell you that he can't. "She's been trying for years to get me to go to a dance class for many, many years..."
Nickname: Diff, and Dai, a Welsh shortform for David.
Worst plane trip: A run of about eight rough landings in Wellington. "One of them was just appalling, the sort where people are throwing up and they all clap and cheer when you finally get down."
Ever dyed your hair? Yes. Tricked into dying it crimson the day before Labour's 1999 election campaign launch. The friendly barber, later outed as a National supporter, assured him the dye would wash out.
NZer of the year? Sam Johnson, from the Christchurch earthquake student army.
Lady Gaga or Rihanna? Rihanna, "definitely."