I have read until around chapter 400, but I have read the novel until near the end, where I dropped because it was clearly going to be rushed, and there were a lot of things I didn't like.
Before I say what I like about this story, I'd really like to address why I dropped the manga much earlier than the novel (which has 1500 and I've read more than 1400). There reason is something they did around said chapter 400.
I'll have to spoil a little bit about the middle and end of the story, but it wasn't a plot twist actually and things naturally went that route, so you have been warned.
The main villain is god. Around chapter 400 Roland hears about the War of Divine Will which is the one the humans are fighting the demons, and discovers that this war was made by god so that only one species remains. See, there is no description of god until this point in the novel, but in the manga, they decided to make an illustration of god instigating the war, with god appearing in the sky while people fight on the land. You could be thinking, "what's the problem?", the problem is the representation of god. They could choose a god of war like Ares, they could choose a trickster god like Loki, or maybe a Chinese god, but nope, this wouldn't be China's Communist Party land if they went with something so neutral. Nope, they choose Jesus. I'm not even Christian anymore and even I see it as anti-christian propaganda.
And I like MGQ, which has a similar premise, with a centralized church based on the catholic church, and an evil god, along with many Christian symbols, like angels. But, it's clearly only BASED on Christian Mythology, not REPRESENTING it. So much so, that despite having female versions of Miguel and Lucifer, there's no depiction or mention of Jesus, nor Jeova. Ilias, the evil god, is actually depicted as an angel. It's very different than simply choosing the mere image of Jesus to represent an evil god, something that came out of nowhere, and has no narrative purpose. If this thing really wants to attract people in the west, they will have to censor that, because Christian gonna be pissed.
That's what made me drop, but there are many things I don't like, beginning with the worst showdown ever. Seriously, Roland vs Zero is the worst showdown ever. They hinted it for so long and made that... I understand there are copyrights to keep in mind, but c'mon, that's the best they can do in that situation. And Roland does even less in the manga than in the novel, which made it even worse.
There's also the bad romance, and the best girl Nightingale being left out until the end of the story. Seriously, Anna may be the first witch, but her personality is so bland, and her intelligence doesn't really convince considering her upbringing.
And let's not forget the CCP influence, with populist policies being portrayed as good, and the masses being portrayed as stupid, or evil, unless they are controlled by the protagonist. The story of Hero is simply unbelievable.
There's more I don't like, for example, the Dream World, and the limit of technology being WW2 instead of WW1 which would be more plausible, but this is already too long.
I seriously wanted to like this manga, it has a great premise and some very good graphics... sometimes. Sometimes they don't even draw the faces, and the male characters are usually ugly. But there are so many things I don't like, that it makes it one more example of the rule "You can't make art under the CCP". Read it if you want it, but try to ignore the propaganda.