One of his earlier efforts, Teens in the Wild, which smacked of a less trashy, less sensationalist version of something you might find on BBC, left me largely unmoved.
But you can't fault the good intentions behind his three-part series Bullyproof, which came to an end last night.
As we've been reminded all too painfully in recent weeks, the cowardly bullying of children by other children -- a rampant vileness that needs to be stamped out -- can take a deep and tragic human toll in terms of young lives prematurely ended and the lives of those who loved and cared for them cruelly, casually destroyed.
Bullyproof was serious, compassionate public service broadcasting.
You can, however, justifiably question whether it served those members of the public, the bullies' victims, who most needed to see it.
The decision to show it at 10.15 on Tuesday nights, a time when many children would either be doing their own thing or heading to bed, in some cases dreading yet another day at school filled with taunts and torments, suggested it was aimed more at parents who need their eyes yanked open.
Fear is a potent force and a child that's being bullied but who, for whatever reason, has been hiding their pain and misery from their parents is hardly likely to sit down and watch it with them.
And I know I'm not the only person (or parent) who wonders whether exposing already vulnerable children to a national television audience is the wisest way to go about tackling the issue.
However well-meant Coleman's series is, there is always the fear that exposure on this scale will simply compound the problem.
Bullyproof frequently made for harrowing viewing, particularly when the children featured.
One boy, Mark (15), who seems like a fine young man, was bullied and jeered over his weight -- and he's by no means what you'd call grossly fat -- to the point where he felt he had to change schools.
His parents spoke emotionally of finding him sitting at the edge of the deepest part of a river, his spirit and sense of self-worth so crushed he was ready to end his life.
Coleman took Mark to a martial arts club where the instructor teaches self-defence techniques kids can use when confronted by bullies.
These have less to do with aggression than with sending out physical signals (standing your ground and holding the other person's gaze, for instance) that you're not victim material.
Thirteen-year-old Jade, another lovely kid, was isolated and called names at school. She's a naturally shy girl, but also naturally, indeed dazzlingly, articulate.
Coleman's strategy was to have her write and deliver a speech about bullying to 120 first-years at her school.
It went brilliantly.
For Mark, Jade and the other children featured, the bullying has now stopped.
While I'm not for a second questioning Coleman's honesty, integrity or professionalism -- at his best, he's one of RTE's finest assets and his programmes an essential counterweight to ratings-chasing rubbish like Supernanny -- I did find myself worrying about what will happen after television's eye has found something else to focus on.
Michael Parkinson, the original king of the Saturday night chat show, has interviewed some of the world's biggest and most fascinating stars, as well as plenty of lesser-famed, but no less intriguing, names.
Yet if you had to pick a single guest from the thousands he's talked to, probably the last one you'd choose would be jazz singer and pianist Jamie CUllum, a man so boring and vanilla-flavoured he makes Michael Buble (another Parky favourite, by the way) seem like Marilyn Manson.
Then again, you're not Parky, who gave Cullum a huge career boost when he was an unknown and who is very much calling the shots on Parkinson: Masterclass, a late-career indulgence that positively drips with safeness and tastefulness.
It's his show, of course, so he can do whatever he wants with it.
But I never thought I'd see the man who wrestled with Rod Hull's Emu turn out something quite so bum-numbingly tedious.
bullyproof 3/5 parkinson: masterclass 1/5