Don't get it twisted.
This manga is good.
For the first half, at least.
I first read this manga a few years back, watched the anime that just aired, and caught up to the manga again just now. And honestly, Vinland saga's story gets worse and worse once you get to the part where the anime drops off. It's a whole completely different story.
Is it a bad thing? Well, yes. The entire genre of the story is basically changed, and so is the pacing. And if I'm being blunt here, I don't quite like the direction the story goes. The story goes from a hardcore blood and iron cutthroat battlefield to a sort of coming of age story that's frankly, kind of mediocre.
I get that Thorfinn had to come to his own conclusion about his father's lessons, so to speak. That was clear very early in the story. However, such a conclusion could be realized without changing the entire genre of the story. Anyways, I can't really agree with how the story came out to be. But, if you like a kind of cheesy coming of age story, you will surely love Vinland Saga's second half. Maybe I'm sulking that the story isn't what I anticipated. Maybe I'm not "cultured" enough to get think that the second part of the story was interesting. Or maybe the second part of the story is just not that good. Hey, I can recognize something as good even if I personally dislike it. And sorry, it's just kind of boring.