I want to call it important rather than good. It's world-changing for Judge Dredd himself. It's telling a story that fandom might have thought would never be told.
Dredd's having doubts. He's questioning the justice system. This is anti-Dredd, since the whole point of the character is to be a fascist bastard... but he is. In the real world, the Soviet bloc was crumbling and it looked as if democracy was taking over. Students protested in Tiananmen Square (and the subsequent massacre wasn't shown on our TV screens). Mikhail Gorbachev was opening up the USSR, pulling out of Afghanistan and opening the door for the 1989 revolutions. The Berlin Wall fell.
The collection I'm reading includes "A Letter to Judge Dredd", a shattering one-part prologue. It destroys Dredd's faith in the system. It also destroyed me, the reader. Damn, it's good. A teenage boy has some innocent questions about the justice system, so he puts them in a letter to Judge Dredd. When I say "questions about", incidentally, I mean "lacerating demolitions of". What's so horrible about it is that the boy trusts the system to be right and is expecting Dredd to have a good reason for, for instance, ordering a clampdown with maximum thuggery on the Democracy March two years ago and giving people brain damage.
Most of the story, though, is Dredd evaluating Rookie Judge Kraken. His clone. Ex-Judda. The boy could almost be Dredd's replacement... and Dredd's cracking up. In one scene, he spouts treason. (They wouldn't call it that, but anyone else saying all that to a Judge's face would probably end up doing time in the cubes.) He goes off the deep end when a perp murders the old judge who did Dredd's own evaluation, all those years ago.
It's shocking. It's reversing all our expectations with this character. But it doesn't really work. Kraken vs. Dredd is like the clash of two robots. We don't care. There's no one to empathise with. In fairness, this would have been an incredibly dramatic story had the change of heart been permanent, or else if Dredd had been even a little bit more of a human being. But he's not. The guy's a block of wood. There's no difference between him and Kraken, really.
It's a shame. In theory, I approve of this story. I like John Wagner's thinking, but I think he's hemmed in by Kraken just not being very interesting (although Dredd releasing the democracy marchers is nice and does everything I'd been missing in the main story). We also know they'll eventually hit a reset button on the character and give Dredd back his jackboots.
It's admirable. It misses its target, but I'm impressed by the fact that it's even trying to get there in the first place.