DYLAN HARTLEY'S old Northampton mate Roger Wilson has vouched for the England hooker as "a top fellah" off the pitch.
That may well be.
On the pitch, the 28-year-old is a different kettle of catfish. He has been shown to be explosive, ill-disciplined and, at times, downright on the wrong side of the game's laws.
The England hooker has had trouble shaking off his tag and bad behaviour has not faded with the onset of maturity.
The rap sheet is there for all to examine.
In 2007, there was the 26-week ban for gouging at the eyes of Wasps James Haskell and Johnny O'Connor.
In 2008, there was the eight-week suspension for biting Stephen Ferris in the Six Nations.
In 2013, Hartley was sent-off in The Premiership final and banned for 11 weeks on foot of his abuse of match referee Wayne Barnes.
Last December, just two months ago, he was banned for three weeks for illegal use of the elbow on Leicester Tigers wing Matt Smith, prompting Saints coach Jim Mallinder to order a serious rethink of his behaviour. Or else.
Oh yes, there was also the minor matter of a two-week enforced break from the game for elbowing Rory Best in a Heineken Cup match in December 2012.
Where it made sense for France to go after Jonathan Sexton, it makes sense for Ireland to test the temper of the man from Rotorua in New Zealand
"A lot has been made about his temperament," said Best.
"But, I think when you play the game like that, sometimes it has strayed the wrong side (of the rules) for him.
"If you look at him, he's a physical player who hits things hard and off the pitch when you chat to him he's a great lad."
There is also caution for the way Hartley can switch from a manic competitor to a composed thrower at the lineout.
"You look at his lineout throwing, whenever he's physical around the pitch he's still able to be cool, calm and collected and throw the ball in and he's very accurate there.
"So if your game-plan is to go out and rattle him, I think you're worrying too much about external factors and certainly if I'm lucky enough to play against him I just want to make sure that my game is right."
Hartley is one of those men everyone outside of England loves to hate.
He does attract negative publicity for his feisty, no surrender attitude and for blurring the line between what is legal and what is not.
The very thing that makes him unpopular is that which makes him a real leader for country and for club.
"You look at some of the stuff he does probably what he brings is more than just being a player," continued Best.
"You look at that Northampton team and when he plays, he's the heartbeat of it and he seems to bring that into his England game
"There's no doubting his rugby ability and off the pitch I certainly have no problems at all with him.
"You know that when he plays he's uncompromising, he's physical, he brings an edge to his game and in that regard you know what to expect."
The Ireland hooker will want to have all his faculties intact after recently following return-to-play protocols from concussion.
Hartley will have to be taken at face value. So too will his fellow forwards as Ireland settle into a battle royal on Sunday.
"I think it is known they are big players, big and physical and we know them quite well from playing against them and in Europe with the provinces," he said.
The expertise of England and Lions forwards coach Graham Rowntree has been stamped all over the forwards," added the 80-times capped forward.
"It is always a tough battle and this Sunday is going to be no different and, obviously, some of us know Graham Rowntree from the Lions, so you know he is going to have them physical and well drilled.
"I think that's probably the exciting thing about playing England, you know you have to be right on your game and right on the edge," concluded Best.