It's really good.
I guess you'll hate it if you can't get over the fact that Sinichi Hiromoto is not a very good artist as far as things like anatomy and generally solid drawing go. This dude has more technical skill, but nonetheless If you think Go Nagai's 70s art for Devilman is utterly irredeemable, you won't like this.
But every other aspect of the art is good and while the style might feel like 'le mall goth edge' at first, you'll realize that it works perfectly with the story. and if you're into emotional expressionist styles you'll like it. The paneling is very cinematic and suggestive and readable, the compositions of the individual drawings are full of inventiveness, especially the facial expressions and poses of the characters. Despite his technical flaws, Hiromoto still manages to make everyone feel like a living human with their own inner drive.
The writing is a fucking fantastic humanization of an absolute monster and a look at what an unflinching belief in "effort and guts" shonen values could do to a sick traumatized mind. But the execution isn't pretentiously reverent; plenty of silly drawings here.
The writing isn't perfect and some plot progressions are a bit wonky, but the thematic and emotional core of the story remains impressive and effective as hell.
Also read it if you're a Go Nagai fan. And I mean an actual fan of Go Nagai who likes his manga. There's clear parallels here to be drawn from the best elements of Devilman and Violence Jack; especially the wonderfully terrifying first arc of the latter.
I'm actually curious too. According to the HnK wiki (so take this with a grain of salt) Buronson says Jagi is his favorite character. I wonder if he read this?
The contrast between heart-warming shonen moments and the sheer emotional horror that proceeds them is pretty nuts. In a good way.
And it doesn't feel like some pretentious "anti-tropey deconstructionist work" either. If this was a normal shonen success story it would still be pretty good. The fact that it goes in a totally different direction only makes it better.
Look at this page. It oozes youthful optimism and yet also has an ominous air to it. Which is perfect given the story context.
That's why I consider this manga is well-drawn; despite failing the /ic/ "objectively correct anatomical stylization" test, it always puts a mirror up to the understanding, sometimes even heart-warming yet deeply dark and depressing story.
and holy shit I love these cartoony dynamic silhouettes
And yes there are 'muh detail' pages if you want those
While I can understand Hardcore FotNS fans not liking it because it has such different goals, on it's own it really is something fantastic and gorgeous and it's misguided to judge it entirely in the context of the main series and not on its own merits.
To be fair, I'd have less reservations recommending it to a Go Nagai fan than a Hokuto no Ken one, especially Nagai's really dark works like Devilman and Violence Jack.
Its sensibilities are more Nagai than Buronson and the author is clearly a Nagai fan; contributed to the Neo Devilman compilation after all.
The entire ending sequence feels like it could have Eva's Komm Susser Tod playing in the background and it would work perfectly. https://www.youtube.com/watch?v=_rcmeMxxGYw And lo and behold Eva is another hugely Nagai-influenced thing.